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André Freitas

dblp:47/9409 · DBLP profile ↗
shortlisted ← Back
98ranked-venue papers
12as first author
59since 2021 · last 2026
0000-0002-4430-4837ORCID · conflict

Domains — the database's venue-derived domains; a paper can count in several

Artificial intelligence and machine learning · 76 · 6 first-author · 47 since 2021Databases, data management, data science and information retrieval · 24 · 8 first-author · 7 since 2021Graphics, computer vision, multimedia, augmented reality and games · 9 · 1 first-author · 7 since 2021Applied, interdisciplinary, general and emerging computing · 6 · 1 first-author · 4 since 2021Human-computer interaction and ubiquitous computing · 4 · 2 first-author · 2 since 2021Systems, architecture and hardware · 1 · 1 first-author

Expertise — from the expertise taxonomy: the topics of the expert's papers under the CCF categories. A weight counts papers with recency: 1 for a paper about the topic, 0.3 when the topic is its context, halved every five years.

Artificial intelligence
25 papers
Language models and text generation · 39% Knowledge representation and reasoning · 18% Trustworthy machine learning · 10%
Databases, data mining, and information retrieval
7 papers
Data integration and cleaning · 40% Information retrieval · 31% Data mining · 24%
Theoretical computer science
4 papers
Automated reasoning and model checking · 100%

Topics — the 30 heaviest of 72, each with the papers that count most for it

TopicWeightPapersLastEvidence papers
Natural language and speech › Language models and text generation › mathematical reasoning
autoformalization
2.032026
FormalScience: Scalable Human-in-the-Loop Autoformalisation of Science with Agentic Code Generation in Lean · ACL (1) 2026
Consistent Autoformalization for Constructing Mathematical Libraries · EMNLP 2024
Verification and Refinement of Natural Language Explanations through LLM-Symbolic Theorem Proving · EMNLP 2024
Natural language and speech › Language models and text generation › natural language understanding › sentence pair modeling
natural language inference
1.422024
Verification and Refinement of Natural Language Explanations through LLM-Symbolic Theorem Proving · EMNLP 2024
NLI4CT: Multi-Evidence Natural Language Inference for Clinical Trial Reports · EMNLP 2023
Data integration and cleaning
entity resolution
1.422025
TableDC: Deep Clustering for Tabular Data · Proc. ACM Manag. Data 2025
Cost-effective Variational Active Entity Resolution · ICDE 2021
Machine learning › Trustworthy machine learning
interpretability
1.432023
Assessing the communication gap between AI models and healthcare professionals: Explainability, utility and trust in AI-driven clinical decision-making · Artif. Intell. 2023
Exploring Knowledge Graphs in an Interpretable Composite Approach for Text Entailment · AAAI 2019
Recognizing and Justifying Text Entailment Through Distributional Navigation on Definition Graphs · AAAI 2018
Natural language and speech › Language models and text generation › model steering › language model steering
activation steering
1.012026
Mitigating Content Effects on Reasoning in Language Models Through Fine-Grained Activation Steering · AAAI 2026
Natural language and speech › Language models and text generation › large language model reasoning › inference-time reasoning
latent reasoning
1.012026
Learning to Disentangle Latent Reasoning Rules with Language VAEs: A Systematic Study · AAAI 2026
Natural language and speech › Language models and text generation › large language model reasoning
reasoning robustness
1.012026
Mitigating Content Effects on Reasoning in Language Models Through Fine-Grained Activation Steering · AAAI 2026
Machine learning › Generative modeling
variational autoencoder
0.922026
Symmetry-induced Disentanglement on Graphs · NeurIPS 2022
Learning to Disentangle Latent Reasoning Rules with Language VAEs: A Systematic Study · AAAI 2026
Knowledge, reasoning and agents › Knowledge representation and reasoning
automated reasoning
0.912025
Faithful and Robust LLM-Driven Theorem Proving for NLI Explanations · ACL (1) 2025
Natural language and speech › Speech recognition and synthesis
automatic speech recognition
0.912025
NEXUS-O: An Omni-Perceptive and -Interactive Model for Language, Audio, and Vision · ACM Multimedia 2025
Natural language and speech › Language models and text generation
chain-of-thought reasoning
0.912025
Improving Chain-of-Thought Reasoning via Quasi-Symbolic Abstractions · ACL (1) 2025
Natural language and speech › Language models and text generation
compositional generalization
0.912025
CARMA: Enhanced Compositionality in LLMs via Advanced Regularisation and Mutual Information Alignment · EMNLP 2025
Knowledge, reasoning and agents › Knowledge representation and reasoning › logic programming
inductive logic programming
0.912025
Inductive Learning of Logical Theories with LLMs: A Expressivity-graded Analysis · AAAI 2025
Natural language and speech › Language models and text generation
large language model reasoning
0.912025
Inductive Learning of Logical Theories with LLMs: A Expressivity-graded Analysis · AAAI 2025
Knowledge, reasoning and agents › Knowledge representation and reasoning
logic-based reasoning
0.912025
Improving Chain-of-Thought Reasoning via Quasi-Symbolic Abstractions · ACL (1) 2025
Computer vision › Vision and language › vision-language model
multimodal large language model
0.912025
NEXUS-O: An Omni-Perceptive and -Interactive Model for Language, Audio, and Vision · ACM Multimedia 2025
Natural language and speech › Language models and text generation › prompting
prompt engineering
0.912025
Controlling Equational Reasoning in Large Language Models with Prompt Interventions · AAAI 2025
Natural language and speech › Machine translation › speech translation
speech-to-speech translation
0.912025
NEXUS-O: An Omni-Perceptive and -Interactive Model for Language, Audio, and Vision · ACM Multimedia 2025
Data mining
clustering
0.912025
TableDC: Deep Clustering for Tabular Data · Proc. ACM Manag. Data 2025
Data mining › clustering
deep clustering
0.912025
TableDC: Deep Clustering for Tabular Data · Proc. ACM Manag. Data 2025
Data integration and cleaning
schema inference
0.912025
TableDC: Deep Clustering for Tabular Data · Proc. ACM Manag. Data 2025
Automated reasoning and model checking › automated reasoning › mathematical reasoning
autoformalization
0.912025
Autoformalization in the Wild: Assessing LLMs on Real-World Mathematical Definitions · EMNLP 2025
Automated reasoning and model checking › theorem proving
interactive theorem proving
0.912025
Autoformalization in the Wild: Assessing LLMs on Real-World Mathematical Definitions · EMNLP 2025
Automated reasoning and model checking › theorem proving › interactive theorem proving
Isabelle/HOL
0.912025
Autoformalization in the Wild: Assessing LLMs on Real-World Mathematical Definitions · EMNLP 2025
Machine learning › Representation and self-supervised learning › representation learning
disentangled representation learning
0.822024
Symmetry-induced Disentanglement on Graphs · NeurIPS 2022
Learning Disentangled Semantic Spaces of Explanations via Invertible Neural Networks · ACL (1) 2024
Knowledge, reasoning and agents › Knowledge representation and reasoning
automated reasoning and model checking
0.812024
Verification and Refinement of Natural Language Explanations through LLM-Symbolic Theorem Proving · EMNLP 2024
Machine learning › Graph learning › graph generation
conditional graph generation
0.812024
Diffusion Twigs with Loop Guidance for Conditional Graph Generation · NeurIPS 2024
Machine learning › Probabilistic and Bayesian machine learning
continuous-time model
0.812024
Graph Neural Flows for Unveiling Systemic Interactions Among Irregularly Sampled Time Series · NeurIPS 2024
Machine learning › Generative modeling
diffusion model
0.812024
Diffusion Twigs with Loop Guidance for Conditional Graph Generation · NeurIPS 2024
Machine learning › Trustworthy machine learning › interpretability
explanation evaluation
0.812024
Inference to the Best Explanation in Large Language Models · ACL (1) 2024

Methods — techniques the papers use, named apart from their topics

large language model · 5.3zero-shot prompting · 2.0self-refinement · 2.0multi-stage agentic approach · 2.0variational autoencoder · 1.6kNN-based conditional steering · 1.0activation steering · 1.0symbolic data generation · 0.9proof sketching · 0.9prompt intervention · 0.9mahalanobis distance · 0.9formal inference engine · 0.9external feedback refinement · 0.9definition grounding · 0.9deep representation learning · 0.9cauchy distribution · 0.9autoformalisation · 0.9LLM prompting · 0.9
YearPublicationVenuePosition
2026 Mitigating Content Effects on Reasoning in Language Models Through Fine-Grained Activation Steering
abstract
Large language models (LLMs) exhibit reasoning biases, often conflating content plausibility with formal logical validity. This can lead to wrong inferences in critical domains, where plausible arguments are incorrectly deemed logically valid or vice versa. This paper investigates how content biases on reasoning can be mitigated through activation steering, an inference-time technique that modulates internal activations. Specifically, after localising the layers responsible for formal and plausible inference, we investigate activation steering on a controlled syllogistic reasoning task, designed to disentangle formal validity from content plausibility. An extensive empirical analysis reveals that contrastive steering methods consistently support linear control over content biases. However, a static approach is insufficient to debias all the tested models. We then investigate how to control content effects by dynamically determining the steering parameters through fine-grained conditional methods. By introducing a novel kNN-based conditional approach (K-CAST), we demonstrate that conditional steering can effectively reduce biases on unresponsive models, achieving up to 15% absolute improvement in formal reasoning accuracy. Finally, we found that steering for content effects is robust to prompt variations, incurs minimal side effects on multilingual language modeling capabilities, and can partially generalize to different reasoning tasks. In practice, we demonstrate that activation-level interventions offer a scalable inference-time strategy for enhancing the robustness of LLMs, contributing towards more systematic and unbiased reasoning capabilities
Marco Valentino, Geonhee Kim, Dhairya Dalal, Zhixue Zhao, André Freitas
AAAI5
2026 Learning to Disentangle Latent Reasoning Rules with Language VAEs: A Systematic Study
Yingji Zhang, Marco Valentino, Danilo S. Carvalho, André Freitas
AAAI4
2026 FormalScience: Scalable Human-in-the-Loop Autoformalisation of Science with Agentic Code Generation in Lean
abstract
Formalising informal mathematical reasoning into formally verifiable code is a significant challenge for large language models. In scientific fields such as physics, domain-specific machinery (e.g. Dirac notation, vector calculus) imposes additional formalisation challenges that modern LLMs and agentic approaches have yet to tackle. To aid autoformalisation in scientific domains, we present FormalScience; a domain-agnostic human-in-the-loop agentic pipeline that enables a single domain expert (without deep formal language experience) to produce syntactically correct and semantically aligned formal proofs of informal reasoning for low economic cost. Applying FormalScience to physics, we construct FormalPhysics, a dataset of 200 university-level (LaTeX) physics problems and solutions (primarily quantum mechanics and electromagnetism), along with their Lean4 formal representations. Compared to existing formal math benchmarks, FormalPhysics achieves perfect formal validity and exhibits greater statement complexity. We evaluate open-source models and proprietary systems on a statement autoformalisation task on our dataset via zero-shot prompting, self-refinement with error feedback, and a novel multi-stage agentic approach, and explore autoformalisation limitations in modern LLM-based approaches. We provide the first systematic characterisation of semantic drift in physics autoformalisation in terms of concepts such as notational collapse and abstraction elevation which reveals what formal language verifies when full semantic preservation is unattainable. We release the codebase together with an interactive UI-based FormalScience system which facilitates autoformalisation and theorem proving in scientific domains beyond physics.[https://github.com/jmeadows17/formal-science]
Jordan Meadows, André Freitas
ACL (1)3
2026 Bridging Linguistic Structure and Mechanistic Interpretability for Conceptual Interpretation in Language Models
abstract
Understanding how language models compose meaning from linguistic input remains a central problem in interpretability research.Mechanistic studies have attributed functional roles to core transformer components; however, these findings derive largely from factual retrieval settings.Whether the same mechanisms support conceptual interpretation, the compositional mapping from definitional expressions to abstract meaning, remains insufficiently characterised.We introduce DSRA (Definitional Semantic Role Analysis), a methodology that applies causal tracing within the reverse dictionary task and augments restoration traces with definitional semantic roles (DSRs) grounded in Argument Structure Theory.This linguistic overlay identifies which compositional functions (e.g., genus, differentia quality) are associated with high-recovery states, extending activation patching beyond token-level localisation.Applied to GPT-J-6B (English) and BERTIN GPT-J-6B (Spanish), the results show that MLP layers associate content-bearing tokens with high-specificity DSR categories in early layers, MHA layers distribute integration across middle-to-upper layers with concentration at the final token, and hidden states aggregate information in upper layers.Alignment between restored states and DSR categories indicates systematic correspondence between internal activations and definitional structure, with consistent localisation patterns across both languages.
Nura Aljaafari, Danilo S. Carvalho, André Freitas
CoNLL3
2025 Controlling Equational Reasoning in Large Language Models with Prompt Interventions
abstract
This paper investigates how hallucination rates in Large Language Models (LLMs) may be controlled via a symbolic data generation framework, exploring a fundamental relationship between the rate of certain mathematical errors and types of input intervention. Specifically, we systematically generate data for a derivation generation task using a symbolic engine, applying targeted interventions to prompts to perturb features of mathematical derivations such as the surface forms of symbols, equational tree structures, and mathematical context. We then evaluate the effect of prompt interventions across a range of LLMs including fine-tuned T5 models, GPT, and LLaMa-based models. Our experiments suggest that T5-Large can outperform the few-shot performance of GPT-4 on various evaluation sets generated via the framework. However, an extensive evaluation based on human analysis, template-based error detection, and text generation metrics reveals model weaknesses beyond what the reference-based metrics singularly describe. We use these results to tie characteristic distributional footprints of interventions to the human evaluation of LLM derivation quality, potentially leading to significant control over fine-grained mathematical capabilities of language models with respect to specific types of errors.
Jordan Meadows, Marco Valentino, André Freitas
AAAI3
2025 Inductive Learning of Logical Theories with LLMs: A Expressivity-graded Analysis
abstract
This work presents a novel systematic methodology to analyse the capabilities and limitations of Large Language Models (LLMs) with feedback from a formal inference engine, on logic theory induction. The analysis is complexity-graded w.r.t. rule dependency structure, allowing quantification of specific inference challenges on LLM performance. Integrating LLMs with formal methods is a promising frontier in the Natural Language Processing field, as an important avenue for improving model inference control and explainability. In particular, inductive learning over complex sets of facts and rules, poses unique challenges for current autoregressive models, as they lack explicit symbolic grounding. While they can be complemented by formal systems, the properties delivered by LLMs regarding inductive learning, are not well understood and quantified. Empirical results indicate that the largest LLMs can achieve competitive results against a SOTA Inductive Logic Programming (ILP) system baseline, but also that tracking long predicate relationship chains is a more difficult obstacle than theory complexity for LLMs.
João Pedro Gandarela de Souza, Danilo S. Carvalho, André Freitas
AAAI3
2025 Faithful and Robust LLM-Driven Theorem Proving for NLI Explanations
abstract
Natural language explanations play a fundamental role in Natural Language Inference (NLI) by revealing how premises logically entail hypotheses.Recent work has shown that the interaction of large language models (LLMs) with theorem provers (TPs) can help verify and improve the validity of NLI explanations.However, TPs require translating natural language into machine-verifiable formal representations, a process that introduces the risk of semantic information loss and unfaithful interpretation, an issue compounded by LLMs' challenges in capturing critical logical structures with sufficient precision.Moreover, LLMs are still limited in their capacity for rigorous and robust proof construction within formal verification frameworks.To mitigate issues related to faithfulness and robustness, this paper investigates strategies to (1) alleviate semantic loss during autoformalisation, (2) efficiently identify and correct syntactic errors in logical representations, (3) explicitly use logical expressions to guide LLMs in generating structured proof sketches, and (4) increase LLMs' capacity of interpreting TP's feedback for iterative refinement.Our empirical results on e-SNLI, QASC and WorldTree using different LLMs demonstrate that the proposed strategies yield significant improvements in autoformalisation (+18.46%,+34.2%, +39.77%) and explanation refinement (+29.5%,+51.5%, +41.25%) over the state-of-the-art model.Moreover, we show that specific interventions on the hybrid LLM-TP architecture can substantially improve efficiency, drastically reducing the number of iterations required for successful verification.1
Marco Valentino, Louise A. Dennis, André Freitas
ACL (1)4
2025 Improving Chain-of-Thought Reasoning via Quasi-Symbolic Abstractions
abstract
Chain-of-Thought (CoT) represents a common strategy for reasoning in Large Language Models (LLMs) by decomposing complex tasks into intermediate inference steps.However, explanations generated via CoT are susceptible to content biases that negatively affect their robustness and faithfulness.To mitigate existing limitations, recent work has proposed the use of logical formalisms coupled with external symbolic solvers.However, fully symbolically formalised approaches introduce the bottleneck of requiring a complete translation from natural language to formal languages, a process that affects efficiency and flexibility.To achieve a trade-off, this paper investigates methods to disentangle content from logical reasoning without a complete formalisation.In particular, we present QuaSAR (for Quasi-Symbolic Abstract Reasoning), a variation of CoT that guides LLMs to operate at a higher level of abstraction via quasi-symbolic explanations.Our framework leverages the capability of LLMs to formalise only relevant variables and predicates, enabling the coexistence of symbolic elements with natural language.We show the impact of QuaSAR for in-context learning and for constructing demonstrations to improve the reasoning capabilities of smaller models.Our experiments show that quasi-symbolic abstractions can improve CoTbased methods by up to 8% accuracy, enhancing robustness and consistency on challenging adversarial variations on both natural language (i.e.MMLU-Redux) and symbolic reasoning tasks (i.e., GSM-Symbolic).
Leonardo Ranaldi, Marco Valentino, André Freitas
ACL (1)3
2025 Montague semantics and modifier consistency measurement in neural language models
abstract
This work proposes a novel methodology for measuring compositional behavior in contemporary language embedding models. Specifically, we focus on adjectival modifier phenomena in adjective-noun phrases. In recent years, distributional language representation models have demonstrated great practical success. At the same time, the need for interpretability has elicited questions on their intrinsic properties and capabilities. Crucially, distributional models are often inconsistent when dealing with compositional phenomena in natural language, which has significant implications for their safety and fairness. Despite this, most current research on compositionality is directed towards improving their performance on similarity tasks only. This work takes a different approach, introducing three novel tests of compositional behavior inspired by Montague semantics. Our experimental results indicate that current neural language models do not behave according to the expected linguistic theories. This indicates that current language models may lack the capability to capture the semantic properties we evaluated on limited context, or that linguistic theories from Montagovian tradition may not match the expected capabilities of distributional models.
Danilo S. Carvalho, Edoardo Manino, Julia Rozanova, Lucas C. Cordeiro, André Freitas
COLING5
2025 Gem: Gaussian Mixture Model Embeddings for Numerical Feature Distributions
Hafiz Tayyab Rauf, Alex Teodor Bogatu, Norman W. Paton, André Freitas
EDBT4
2025 CARMA: Enhanced Compositionality in LLMs via Advanced Regularisation and Mutual Information Alignment
abstract
Large language models (LLMs) struggle with compositional generalisation, limiting their ability to systematically combine learned components to interpret novel inputs.While architectural modifications, fine-tuning, and data augmentation improve compositionality, they often have limited adaptability, face scalability constraints, or yield diminishing returns on real data.To address this, we propose CARMA, an intervention that enhances the stability and robustness of compositional reasoning in LLMs while preserving fine-tuned performance.CARMA employs mutual information regularisation and layer-wise stability constraints to mitigate feature fragmentation, ensuring structured representations persist across and within layers.We evaluate CARMA on inverse dictionary modelling and sentiment classification, measuring its impact on semantic consistency, performance stability, and robustness to lexical perturbations.Results show that CARMA reduces the variability introduced by fine-tuning, stabilises token representations, and improves compositional reasoning.While its effectiveness varies across architectures, CARMA's key strength lies in reinforcing learned structures rather than introducing new capabilities, making it a scalable auxiliary method.These findings suggest that integrating CARMA with fine-tuning can improve compositional generalisation while maintaining task-specific performance in LLMs.
Nura Aljaafari, Danilo S. Carvalho, André Freitas
EMNLP3
2025 Autoformalization in the Wild: Assessing LLMs on Real-World Mathematical Definitions
abstract
Thanks to their linguistic capabilities, LLMs offer an opportunity to bridge the gap between informal mathematics and formal languages through autoformalization.However, it is still unclear how well LLMs generalize to sophisticated and naturally occurring mathematical statements.To address this gap, we investigate the task of autoformalizing real-world mathematical definitions: a critical component of mathematical discourse.Specifically, we introduce two novel resources for autoformalization, collecting definitions from Wikipedia (Def_Wiki) and arXiv papers (Def_ArXiv).We then systematically evaluate a range of LLMs, analyzing their ability to formalize definitions into Isabelle/HOL.Furthermore, we investigate strategies to enhance LLMs' performance including refinement through external feedback from Proof Assistants, and formal definition grounding, where we augment LLMs' formalizations through relevant contextual elements from formal mathematical libraries.Our findings reveal that definitions present a greater challenge compared to existing benchmarks, such as miniF2F.In particular, we found that LLMs still struggle with self-correction, and aligning with relevant mathematical libraries.At the same time, structured refinement methods and definition grounding strategies yield notable improvements of up to 16% on selfcorrection capabilities and 43% on the reduction of undefined errors, highlighting promising directions for enhancing LLM-based autoformalization in real-world scenarios.1
Marco Valentino, André Freitas
EMNLP3
2025 Effective Graph and Rank-based Contextual Embeddings for Textual and Multimedia Data
abstract
In a data-driven world, efficiently organizing and mapping relationships between objects is crucial. Graphs are powerful tools for modeling these connections, being widely used in social networks, telecommunications, and biology. However, graph-based methods often face high computational costs, particularly in memory and space usage. To address this, graph embedding techniques, also referred to as Network Representation Learning, encode graph information into lower-dimensional representations while preserving structural aspects. Traditional methods, however, lack interpretable dimensions. RaDE (Rank Diffusion Embedding) introduces a new approach using rank-based information, with a key step being the selection of a representative subset of nodes to provide interpretability for its dimensions and improve retrieval tasks. Despite its potential, RaDE’s original proposal did not fully explore the effectiveness of representative subset selection across different classes or evaluate embeddings in tasks like classification and clustering. Inspired by RaDE, this work introduces GRaCE (Graph and Rank-based Contextual Embeddings), a fully unsupervised framework that generates interpretable embeddings by leveraging robust rank-based measures for representative subset selection and node embedding. GRaCE surpasses RaDE and Original Features across diverse datasets, including textual and image collections, excelling in retrieval, classification, and clustering tasks, considering state-of-the-art Transformer models as feature descriptors and Graph Convolutional Networks models in classification tasks.
Thiago César Castilho Almeida, Gustavo Leticio, Lucas Pascotti Valem, André Freitas, Daniel C. G. Pedronette
IJCNN4
2025 NEXUS-O: An Omni-Perceptive and -Interactive Model for Language, Audio, and Vision
abstract
Human beings perceive the real world through a spectrum of sensory modalities, encompassing auditory, visual, and linguistic faculties. This work proposes an industry-level omni-modal large language model (LLM) pipeline that integrates auditory, visual, and linguistic modalities to overcome challenges such as limited tri-modal datasets, high computational costs, and complex feature alignments. Our pipeline consists of three main components: First, a modular, end-to-end framework enabling flexible configuration of various encoder-LLM-decoder architectures. Second, a lightweight training strategy that pre-trains audio-language alignment on the state-of-the-art vision-language model Qwen2.5-VL, thus avoiding the costly pre-training of vision-specific modalities. Third, an audio synthesis pipeline that generates high-quality audio-text data from diverse real-world scenarios, supporting applications such as Automatic Speech Recognition and Speech-to-Speech chat. To this end, we introduce an industry-level omni-modal LLM, NEXUS-O. Extensive experiments validate the efficacy of our pipeline, yielding the following key findings: (1) In the visual understanding task, NEXUSO exhibits superior performance compared with its backbone model - Qwen2.5-VL-7B, validating the efficiency of our training strategy. (2) Within the English Spoken Question-Answering task, the model achieves better accuracy than the same-period competitor (i.e, MiniCPM-o2.6-7B) in the LLaMA Q. benchmark. (3) In our realworld ASR testset, NEXUS-O achieves outstanding performance, indicating its robustness in real scenarios. (4) In the Speech-to-Text Translation task, our model outperforms Qwen2-Audio-Instruct-7B. (5) In the Text-to-Speech task, based on pretrained vocoder (e.g., Fishspeech1.4 or CosyVoice2.0), NEXUS-O is comparable to its backbone vocoder on Seed-TTS benchmark. (6) An in-depth analysis of tri-modal alignment reveals that incorporating the audio modality enhances representational alignment between vision and language.
Che Liu 0002, Yingji Zhang, Chenggong Gong, Yu Lu 0020, Shilin Zhou 0002, Ziliang Gan, Haipang Wu, Ji Liu 0003, André Freitas, Qifan Wang 0001, Zenglin Xu, Rongjunchen Zhang, Yong Dai 0001
ACM Multimedia12
2025 Eliciting Critical Reasoning in Retrieval-Augmented Generation via Contrastive Explanations
abstract
Leonardo Ranaldi, Marco Valentino, Andre Freitas. Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers). 2025.
Leonardo Ranaldi, Marco Valentino, André Freitas
NAACL (Long Papers)3
2025 SylloBio-NLI: Evaluating Large Language Models on Biomedical Syllogistic Reasoning
abstract
Magdalena Wysocka, Danilo Carvalho, Oskar Wysocki, Marco Valentino, Andre Freitas. Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers). 2025.
Magdalena Wysocka, Danilo S. Carvalho, Oskar Wysocki, Marco Valentino, André Freitas
NAACL (Long Papers)5
2025 TableDC: Deep Clustering for Tabular Data
abstract
Deep clustering (DC), a fusion of deep representation learning and clustering, has recently demonstrated positive results in data science, particularly text processing and computer vision. However, joint optimization of feature learning and data distribution in the multi-dimensional space is domain-specific, so existing DC methods struggle to generalize to other application domains (such as data integration). In data management tasks, where high-density embeddings and overlapping clusters dominate, a data management-specific DC algorithm should be able to interact better with the data properties to support data integration tasks. This paper presents a deep clustering algorithm for tabular data (TableDC) that reflects the properties of data management applications that cluster tables (schema inference), rows (entity resolution) and columns (domain discovery). To address overlapping clusters, TableDC integrates Mahalanobis distance, which considers variance and correlation within the data, offering a similarity method suitable for tabular data in high-dimensional latent spaces. TableDC also shows higher tolerance to outliers through its heavy-tailed Cauchy distribution as the similarity kernel. The proposed similarity measure is particularly beneficial where the embeddings of raw data are densely packed and exhibit high degrees of overlap. Data integration tasks may also involve large numbers of clusters, which challenges the scalability of existing DC methods. TableDC learns data embeddings with a large number of clusters more efficiently than baseline DC methods, which scale in quadratic time. We evaluated TableDC with several existing DC, Standard Clustering (SC), and state-of-the-art bespoke methods over benchmark datasets. TableDC consistently outperforms existing DC, SC and bespoke methods.
Hafiz Tayyab Rauf, André Freitas, Norman W. Paton
Proc. ACM Manag. Data2
2024 Inference to the Best Explanation in Large Language Models
abstract
While Large Language Models (LLMs) have found success in real-world applications, their underlying explanatory process is still poorly understood.This paper proposes IBE-Eval, a framework inspired by philosophical accounts on Inference to the Best Explanation (IBE) to advance the interpretation and evaluation of LLM explanations.IBE-Eval estimates the plausibility of natural language explanations through a combination of explicit logical and linguistic features including: consistency, parsimony, coherence, and uncertainty.Extensive experiments are conducted on Causal Question Answering (CQA), where IBE-Eval is tasked to select the most plausible causal explanation amongst competing ones generated by the LLM (e.g.GPT 3.5 or LLaMA 2).The experiments reveal that IBE-Eval can successfully identify the best explanation with up to 77% accuracy (≈ 27% above random), improving upon a GPT 3.5-as-a-judge baseline (≈ +17%) while being intrinsically more efficient and interpretable.Additional analysis suggests that, despite LLM-specific variances, generated explanations tend to conform to IBE criteria and that IBE-Eval is significantly correlated with human judgment, opening up opportunities for future development of automated explanation verification tools. Inference to the Best Explanation (IBE)
Dhairya Dalal, Marco Valentino, André Freitas, Paul Buitelaar
ACL (1)3
2024 Learning Disentangled Semantic Spaces of Explanations via Invertible Neural Networks
abstract
Disentangled latent spaces usually have better semantic separability and geometrical properties, which leads to better interpretability and more controllable data generation. While this has been well investigated in Computer Vision, in tasks such as image disentanglement, in the NLP domain, sentence disentanglement is still comparatively under-investigated. Most previous work have concentrated on disentangling task-specific generative factors, such as sentiment, within the context of style transfer. In this work, we focus on a more general form of sentence disentanglement, targeting the localised modification and control of more general sentence semantic features. To achieve this, we contribute to a novel notion of sentence semantic disentanglement and introduce a flow-based invertible neural network (INN) mechanism integrated with a transformer-based language Autoencoder (AE) in order to deliver latent spaces with better separability properties. Experimental results demonstrate that the model can conform the distributed latent space into a better semantically disentangled sentence space, leading to improved language interpretability and controlled generation when compared to the recent state-of-the-art language VAE models.
Yingji Zhang, Danilo S. Carvalho, André Freitas
ACL (1)3
2024 Estimating the Causal Effects of Natural Logic Features in Transformer-Based NLI Models
abstract
Rigorous evaluation of the causal effects of semantic features on language model predictions can be hard to achieve for natural language reasoning problems. However, this is such a desirable form of analysis from both an interpretability and model evaluation perspective, that it is valuable to investigate specific patterns of reasoning with enough structure and regularity to identify and quantify systematic reasoning failures in widely-used models. In this vein, we pick a portion of the NLI task for which an explicit causal diagram can be systematically constructed: the case where across two sentences (the premise and hypothesis), two related words/terms occur in a shared context. In this work, we apply causal effect estimation strategies to measure the effect of context interventions (whose effect on the entailment label is mediated by the semantic monotonicity characteristic) and interventions on the inserted word-pair (whose effect on the entailment label is mediated by the relation between these words). Extending related work on causal analysis of NLP models in different settings, we perform an extensive interventional study on the NLI task to investigate robustness to irrelevant changes and sensitivity to impactful changes of Transformers. The results strongly bolster the fact that similar benchmark accuracy scores may be observed for models that exhibit very different behaviour. Moreover, our methodology reinforces previously suspected biases from a causal perspective, including biases in favour of upward-monotone contexts and ignoring the effects of negation markers.
Julia Rozanova, Marco Valentino, André Freitas
LREC/COLING3
2024 A Differentiable Integer Linear Programming Solver for Explanation-Based Natural Language Inference
abstract
Integer Linear Programming (ILP) has been proposed as a formalism for encoding precise structural and semantic constraints for Natural Language Inference (NLI). However, traditional ILP frameworks are non-differentiable, posing critical challenges for the integration of continuous language representations based on deep learning. In this paper, we introduce a novel approach, named Diff-Comb Explainer, a neuro-symbolic architecture for explanation-based NLI based on Differentiable BlackBox Combinatorial Solvers (DBCS). Differently from existing neuro-symbolic solvers, Diff-Comb Explainer does not necessitate a continuous relaxation of the semantic constraints, enabling a direct, more precise, and efficient incorporation of neural representations into the ILP formulation. Our experiments demonstrate that Diff-Comb Explainer achieves superior performance when compared to conventional ILP solvers, neuro-symbolic black-box solvers, and Transformer-based encoders. Moreover, a deeper analysis reveals that Diff-Comb Explainer can significantly improve the precision, consistency, and faithfulness of the constructed explanations, opening new opportunities for research on neuro-symbolic architectures for explainable and transparent NLI in complex domains.
Mokanarangan Thayaparan, Marco Valentino, André Freitas
LREC/COLING3
2024 Enhancing Ethical Explanations of Large Language Models through Iterative Symbolic Refinement
abstract
An increasing amount of research in Natural Language Inference (NLI) focuses on the application and evaluation of Large Language Models (LLMs) and their reasoning capabilities.Despite their success, however, LLMs are still prone to factual errors and inconsistencies in their explanations, offering limited control and interpretability for inference in complex domains.In this paper, we focus on ethical NLI, investigating how hybrid neurosymbolic techniques can enhance the logical validity and alignment of ethical explanations produced by LLMs.Specifically, we present an abductive-deductive framework named Logic-Explainer, which integrates LLMs with an external backward-chaining solver to refine step-wise natural language explanations and jointly verify their correctness, reduce incompleteness and minimise redundancy.An extensive empirical analysis demonstrates that Logic-Explainer can improve explanations generated via in-context learning methods and Chainof-Thought (CoT) on challenging ethical NLI tasks, while, at the same time, producing formal proofs describing and supporting models' reasoning.As ethical NLI requires commonsense reasoning to identify underlying moral violations, our results suggest the effectiveness of neuro-symbolic methods for multi-step NLI more broadly, opening new opportunities to enhance the logical consistency, reliability, and alignment of LLMs.
Marco Valentino, Louise A. Dennis, André Freitas
EACL (1)4
2024 Aligning Large and Small Language Models via Chain-of-Thought Reasoning
abstract
Chain-of-Thought (CoT) prompting empowers the reasoning abilities of Large Language Models (LLMs), eliciting them to solve complex reasoning tasks in a step-wise manner.However, these abilities appear only in models with billions of parameters, which represent an entry barrier for many users who are constrained to operate on a smaller model scale, i.e., Small Language Models (SLMs).Although many companies are releasing LLMs of the same family with fewer parameters, these models tend not to preserve all the reasoning capabilities of the original models, including CoT reasoning.In this paper, we propose a method for aligning and transferring reasoning abilities between larger to smaller Language Models.By using an Instruction-tuning-CoT method, an Instruction-tuning designed around CoT-Demonstrations, we enable the SLMs to generate multi-step controlled reasoned answers when elicited with the CoT mechanism.Hence, we instruct a smaller Language Model using outputs generated by more robust models belonging to the same family or not, evaluating the impact across different types of models.Results obtained on question-answering and mathematical reasoning benchmarks show that LMs instructed via the Instruction-tuning CoT method produced by LLMs outperform baselines within both in-domain and out-domain scenarios.
Leonardo Ranaldi, André Freitas
EACL (1)2
2024 Multi-Relational Hyperbolic Word Embeddings from Natural Language Definitions
abstract
Natural language definitions possess a recursive, self-explanatory semantic structure that can support representation learning methods able to preserve explicit conceptual relations and constraints in the latent space.This paper presents a multi-relational model that explicitly leverages such a structure to derive word embeddings from definitions.By automatically extracting the relations linking defined and defining terms from dictionaries, we demonstrate how the problem of learning word embeddings can be formalised via a translational framework in Hyperbolic space and used as a proxy to capture the global semantic structure of definitions.An extensive empirical analysis demonstrates that the framework can help imposing the desired structural constraints while preserving the semantic mapping required for controllable and interpretable traversal.Moreover, the experiments reveal the superiority of the Hyperbolic word embeddings over the Euclidean counterparts and demonstrate that the multirelational approach can obtain competitive results when compared to state-of-the-art neural models, with the advantage of being intrinsically more efficient and interpretable 1 .
Marco Valentino, Danilo S. Carvalho, André Freitas
EACL (1)3
2024 Deep Clustering for Data Cleaning and Integration
Hafiz Tayyab Rauf, André Freitas, Norman W. Paton
EDBT2
2024 Verification and Refinement of Natural Language Explanations through LLM-Symbolic Theorem Proving
abstract
Natural language explanations represent a proxy for evaluating explanation-based and multi-step Natural Language Inference (NLI) models.However, assessing the validity of explanations for NLI is challenging as it typically involves the crowd-sourcing of apposite datasets, a process that is time-consuming and prone to logical errors.To address existing limitations, this paper investigates the verification and refinement of natural language explanations through the integration of Large Language Models (LLMs) and Theorem Provers (TPs).Specifically, we present a neuro-symbolic framework, named Explanation-Refiner, that integrates TPs with LLMs to generate and formalise explanatory sentences and suggest potential inference strategies for NLI.In turn, the TP is employed to provide formal guarantees on the logical validity of the explanations and to generate feedback for subsequent improvements.We demonstrate how Explanation-Refiner can be jointly used to evaluate explanatory reasoning, autoformalisation, and error correction mechanisms of state-of-the-art LLMs as well as to automatically enhance the quality of explanations of variable complexity in different domains. 1
Marco Valentino, Louise A. Dennis, André Freitas
EMNLP4
2024 Self-Refine Instruction-Tuning for Aligning Reasoning in Language Models
abstract
The alignment of reasoning abilities between smaller and larger Language Models are largely conducted via supervised fine-tuning using demonstrations generated from robust Large Language Models (LLMs).Although these approaches deliver more performant models, they do not show sufficiently strong generalization as the training only relies on the provided demonstrations.In this paper, we propose a self-refine Instruction-tuning method that allows for Smaller Language Models to self-improve their reasoning abilities.Our approach is based on a two-stage process, where reasoning abilities are first transferred between LLMs and Small Language Models (SLMs) via Instruction-tuning on synthetic demonstrations provided by LLMs, and then the instructed models self-improve through preference optimization strategies.In particular, the second phase operates refinement heuristics based on Direct Preference Optimization, where the SLMs are prompted to deliver a series of reasoning paths by automatically sampling the generated responses and providing rewards using ground truths from the LLMs.Results obtained on commonsense and math reasoning tasks show that this approach consistently outperforms Instructiontuning in both in-domain and out-domain scenarios, aligning the reasoning abilities of smaller and larger language models.
Leonardo Ranaldi, André Freitas
EMNLP2
2024 Consistent Autoformalization for Constructing Mathematical Libraries
abstract
Autoformalization is the task of automatically translating mathematical content written in natural language to a formal language expression.The growing language interpretation capabilities of Large Language Models (LLMs), including in formal languages, are lowering the barriers for autoformalization.However, LLMs alone are not capable of consistently and reliably delivering autoformalization, in particular as the complexity and specialization of the target domain grows.As the field evolves into the direction of systematically applying autoformalization towards large mathematical libraries, the need to improve syntactic, terminological and semantic control increases.This paper proposes the coordinated use of three mechanisms, most-similar retrieval augmented generation (MS-RAG), denoising steps, and autocorrection with syntax error feedback (Auto-SEF) to improve autoformalization quality.The empirical analysis, across different models, demonstrates that these mechanisms can deliver autoformalizaton results which are syntactically, terminologically and semantically more consistent.These mechanisms can be applied across different LLMs and have shown to deliver improve results across different model types. 1
André Freitas
EMNLP3
2024 A Symbolic Framework for Evaluating Mathematical Reasoning and Generalisation with Transformers
abstract
Jordan Meadows, Marco Valentino, Damien Teney, Andre Freitas. Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers). 2024.
Jordan Meadows, Marco Valentino, Damien Teney, André Freitas
NAACL-HLT4
2024 Multi-Operational Mathematical Derivations in Latent Space
abstract
Marco Valentino, Jordan Meadows, Lan Zhang, Andre Freitas. Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers). 2024.
Marco Valentino, Jordan Meadows, André Freitas
NAACL-HLT4
2024 Graph Neural Flows for Unveiling Systemic Interactions Among Irregularly Sampled Time Series
abstract
Interacting systems are prevalent in nature. It is challenging to accurately predict the dynamics of the system if its constituent components are analyzed independently. We develop a graph-based model that unveils the systemic interactions of time series observed at irregular time points, by using a directed acyclic graph to model the conditional dependencies (a form of causal notation) of the system components and learning this graph in tandem with a continuous-time model that parameterizes the solution curves of ordinary differential equations (ODEs). Our technique, a graph neural flow, leads to substantial enhancements over non-graph-based methods, as well as graph-based methods without the modeling of conditional dependencies. We validate our approach on several tasks, including time series classification and forecasting, to demonstrate its efficacy.
Giangiacomo Mercatali, André Freitas
NeurIPS2
2024 Diffusion Twigs with Loop Guidance for Conditional Graph Generation
abstract
We introduce a novel score-based diffusion framework named Twigs that incorporates multiple co-evolving flows for enriching conditional generation tasks. Specifically, a central or trunk diffusion process is associated with a primary variable (e.g., graph structure), and additional offshoot or stem processes are dedicated to dependent variables (e.g., graph properties or labels). A new strategy, which we call loop guidance, effectively orchestrates the flow of information between the trunk and the stem processes during sampling. This approach allows us to uncover intricate interactions and dependencies, and unlock new generative capabilities. We provide extensive experiments to demonstrate strong performance gains of the proposed method over contemporary baselines in the context of conditional graph generation, underscoring the potential of Twigs in challenging generative tasks such as inverse molecular design and molecular optimization. Code is available at https://github.com/Aalto-QuML/Diffusion_twigs.
Giangiacomo Mercatali, Yogesh Verma, André Freitas, Vikas Garg 0001
NeurIPS3
2024 Relation Extraction in Underexplored Biomedical Domains: A Diversity-optimized Sampling and Synthetic Data Generation Approach
abstract
Abstract The sparsity of labeled data is an obstacle to the development of Relation Extraction (RE) models and the completion of databases in various biomedical areas. While being of high interest in drug-discovery, the literature on natural products, reporting the identification of potential bioactive compounds from organisms, is a concrete example of such an overlooked topic. To mark the start of this new task, we created the first curated evaluation dataset and extracted literature items from the LOTUS database to build training sets. To this end, we developed a new sampler, inspired by diversity metrics in ecology, named Greedy Maximum Entropy sampler (https://github.com/idiap/gme-sampler). The strategic optimization of both balance and diversity of the selected items in the evaluation set is important given the resource-intensive nature of manual curation. After quantifying the noise in the training set, in the form of discrepancies between the text of input abstracts and the expected output labels, we explored different strategies accordingly. Framing the task as an end-to-end Relation Extraction, we evaluated the performance of standard fine-tuning (BioGPT, GPT-2, and Seq2rel) and few-shot learning with open Large Language Models (LLMs) (LLaMA 7B-65B). In addition to their evaluation in few-shot settings, we explore the potential of open LLMs as synthetic data generators and propose a new workflow for this purpose. All evaluated models exhibited substantial improvements when fine-tuned on synthetic abstracts rather than the original noisy data. We provide our best performing (F1-score = 59.0) BioGPT-Large model for end-to-end RE of natural products relationships along with all the training and evaluation datasets. See more details at https://github.com/idiap/abroad-re.
Maxime Delmas 0001, Magdalena Wysocka, André Freitas
Comput. Linguistics3
2024 Large Language Models, scientific knowledge and factuality: A framework to streamline human expert evaluation
abstract
OBJECTIVE: The paper introduces a framework for the evaluation of the encoding of factual scientific knowledge, designed to streamline the manual evaluation process typically conducted by domain experts. Inferring over and extracting information from Large Language Models (LLMs) trained on a large corpus of scientific literature can potentially define a step change in biomedical discovery, reducing the barriers for accessing and integrating existing medical evidence. This work explores the potential of LLMs for dialoguing with biomedical background knowledge, using the context of antibiotic discovery. METHODS: The framework involves three evaluation steps, each assessing different aspects sequentially: fluency, prompt alignment, semantic coherence, factual knowledge, and specificity of the generated responses. By splitting these tasks between non-experts and experts, the framework reduces the effort required from the latter. The work provides a systematic assessment on the ability of eleven state-of-the-art LLMs, including ChatGPT, GPT-4 and Llama 2, in two prompting-based tasks: chemical compound definition generation and chemical compound-fungus relation determination. RESULTS: Although recent models have improved in fluency, factual accuracy is still low and models are biased towards over-represented entities. The ability of LLMs to serve as biomedical knowledge bases is questioned, and the need for additional systematic evaluation frameworks is highlighted. CONCLUSION: While LLMs are currently not fit for purpose to be used as biomedical factual knowledge bases in a zero-shot setting, there is a promising emerging property in the direction of factuality as the models become domain specialised, scale up in size and level of human feedback.
Magdalena Wysocka, Oskar Wysocki, Maxime Delmas 0001, Vincent Mutel, André Freitas
J. Biomed. Informatics5
2023 NLI4CT: Multi-Evidence Natural Language Inference for Clinical Trial Reports
abstract
How can we interpret and retrieve medical evidence to support clinical decisions?Clinical trial reports (CTR) amassed over the years contain indispensable information for the development of personalized medicine.However, it is practically infeasible to manually inspect over 400,000+ clinical trial reports in order to find the best evidence for experimental treatments.Natural Language Inference (NLI) offers a potential solution to this problem, by allowing the scalable computation of textual entailment.However, existing NLI models perform poorly on biomedical corpora, and previously published datasets fail to capture the full complexity of inference over CTRs.In this work, we present a novel resource to advance research on NLI for reasoning on CTRs.The resource includes two main tasks.Firstly, to determine the inference relation between a natural language statement, and a CTR.Secondly, to retrieve supporting facts to justify the predicted relation.We provide NLI4CT, a corpus of 2400 statements and CTRs, annotated for these tasks.Baselines on this corpus expose the limitations of existing NLI approaches, with 6 state-of-the-art NLI models achieving a maximum F1 score of 0.627.To the best of our knowledge, we are the first to design a task that covers the interpretation of full CTRs.To encourage further work on this challenging dataset, we make the corpus, competition leaderboard, and website, available on CodaLab, and code to replicate the baseline experiments on GitHub 1 .
Maël Jullien, Marco Valentino, Hannah Frost, Paul O'Regan, Donal Landers, André Freitas
EMNLP6
2023 Mystery in the Ecological Park: An Interactive Narrative to Promote Interaction with Biodiversity
André Freitas, Francisco Fernandes, Mara Dionisio, Sandra Câmara Olim
ICEC1
2023 Assessing the communication gap between AI models and healthcare professionals: Explainability, utility and trust in AI-driven clinical decision-making
abstract
This paper contributes with a pragmatic evaluation framework for explainable Machine Learning (ML) models for clinical decision support. The study revealed a more nuanced role for ML explanation models, when these are pragmatically embedded in the clinical context. Despite the general positive attitude of healthcare professionals (HCPs) towards explanations as a safety and trust mechanism, for a significant set of participants there were negative effects associated with confirmation bias, accentuating model over-reliance and increased effort to interact with the model. Also, contradicting one of its main intended functions, standard explanatory models showed limited ability to support a critical understanding of the limitations of the model. However, we found new significant positive effects which repositions the role of explanations within a clinical context: these include reduction of automation bias, addressing ambiguous clinical cases (cases where HCPs were not certain about their decision) and support of less experienced HCPs in the acquisition of new domain knowledge.
Oskar Wysocki, Jessica Katharine Davies, Markel Vigo, Anne Caroline Armstrong, Donal Landers, Rebecca Lee, André Freitas
Artif. Intell.7
2023 A systematic review of biologically-informed deep learning models for cancer: fundamental trends for encoding and interpreting oncology data
abstract
BACKGROUND: There is an increasing interest in the use of Deep Learning (DL) based methods as a supporting analytical framework in oncology. However, most direct applications of DL will deliver models with limited transparency and explainability, which constrain their deployment in biomedical settings. METHODS: This systematic review discusses DL models used to support inference in cancer biology with a particular emphasis on multi-omics analysis. It focuses on how existing models address the need for better dialogue with prior knowledge, biological plausibility and interpretability, fundamental properties in the biomedical domain. For this, we retrieved and analyzed 42 studies focusing on emerging architectural and methodological advances, the encoding of biological domain knowledge and the integration of explainability methods. RESULTS: We discuss the recent evolutionary arch of DL models in the direction of integrating prior biological relational and network knowledge to support better generalisation (e.g. pathways or Protein-Protein-Interaction networks) and interpretability. This represents a fundamental functional shift towards models which can integrate mechanistic and statistical inference aspects. We introduce a concept of bio-centric interpretability and according to its taxonomy, we discuss representational methodologies for the integration of domain prior knowledge in such models. CONCLUSIONS: The paper provides a critical outlook into contemporary methods for explainability and interpretability used in DL for cancer. The analysis points in the direction of a convergence between encoding prior knowledge and improved interpretability. We introduce bio-centric interpretability which is an important step towards formalisation of biological interpretability of DL models and developing methods that are less problem- or application-specific.
Magdalena Wysocka, Oskar Wysocki, Marie Zufferey, Donal Landers, André Freitas
BMC Bioinform.5
2023 Transformers and the Representation of Biomedical Background Knowledge
abstract
Abstract Specialized transformers-based models (such as BioBERT and BioMegatron) are adapted for the biomedical domain based on publicly available biomedical corpora. As such, they have the potential to encode large-scale biological knowledge. We investigate the encoding and representation of biological knowledge in these models, and its potential utility to support inference in cancer precision medicine—namely, the interpretation of the clinical significance of genomic alterations. We compare the performance of different transformer baselines; we use probing to determine the consistency of encodings for distinct entities; and we use clustering methods to compare and contrast the internal properties of the embeddings for genes, variants, drugs, and diseases. We show that these models do indeed encode biological knowledge, although some of this is lost in fine-tuning for specific tasks. Finally, we analyze how the models behave with regard to biases and imbalances in the dataset.
Oskar Wysocki, Paul O'Regan, Deborah Ferreira, Magdalena Wysocka, Donal Landers, André Freitas
Comput. Linguistics7
2023 Meta-analysis informed machine learning: Supporting cytokine storm detection during CAR-T cell Therapy
abstract
Cytokine release syndrome (CRS), also known as cytokine storm, is one of the most consequential adverse effects of chimeric antigen receptor therapies that have shown otherwise promising results in cancer treatment. When emerging, CRS could be identified by the analysis of specific cytokine and chemokine profiles that tend to exhibit similarities across patients. In this paper, we exploit these similarities using machine learning algorithms and set out to pioneer a meta-review informed method for the identification of CRS based on specific cytokine peak concentrations and evidence from previous clinical studies. To this end we also address a widespread challenge of the applicability of machine learning in general: reduced training data availability. We do so by augmenting available (but often insufficient) patient cytokine concentrations with statistical knowledge extracted from domain literature. We argue that such methods could support clinicians in analyzing suspect cytokine profiles by matching them against the said CRS knowledge from past clinical studies, with the ultimate aim of swift CRS diagnosis. We evaluate our proposed methods under several design choices, achieving performance of more than 90% in terms of CRS identification accuracy, and showing that many of our choices outperform a purely data-driven alternative. During evaluation with real-world CRS clinical data, we emphasize the potential of our proposed method of producing interpretable results, in addition to being effective in identifying the onset of cytokine storm.
Alex Teodor Bogatu, Magdalena Wysocka, Oskar Wysocki, Holly Butterworth, Manon Pillai, Jennifer Allison, Donal Landers, Elaine Kilgour, Fiona Thistlethwaite, André Freitas
J. Biomed. Informatics10
2023 A Canonical Context-Preserving Representation for Open IE: Extracting Semantically Typed Relational Tuples from Complex Sentences
abstract
Modern systems that deal with inference in texts need automatized methods to extract meaning representations (MRs) from texts at scale. Open Information Extraction (IE) is a prominent way of extracting all potential relations from a given text in a comprehensive manner. Previous work in this area has mainly focused on the extraction of isolated relational tuples. Ignoring the cohesive nature of texts where important contextual information is spread across clauses or sentences, state-of-the-art Open IE approaches are thus prone to generating a loose arrangement of tuples that lack the expressiveness needed to infer the true meaning of complex assertions. To overcome this limitation, we present a method that allows existing Open IE systems to enrich their output with additional meta information. By leveraging the semantic hierarchy of minimal propositions generated by the discourse-aware Text Simplification (TS) approach presented in Niklaus et al. (2019), we propose a mechanism to extract semantically typed relational tuples from complex source sentences. Based on this novel type of output, we introduce a lightweight semantic representation for Open IE in the form of normalized and context-preserving relational tuples. It extends the shallow semantic representation of state-of-the-art approaches in the form of predicate-argument structures by capturing intra-sentential rhetorical structures and hierarchical relationships between the relational tuples. In that way, the semantic context of the extracted tuples is preserved, resulting in more informative and coherent predicate-argument structures which are easier to interpret. In addition, in a comparative analysis, we show that the semantic hierarchy of minimal propositions benefits Open IE approaches in a second dimension: the canonical structure of the simplified sentences is easier to process and analyze, and thus facilitates the extraction of relational tuples, resulting in an improved precision (up to 32%) and recall (up to 30%) of the extracted relations on a large benchmark corpus.
Christina Niklaus, Matthias Cetto, André Freitas, Siegfried Handschuh
Knowl. Based Syst.3
2023 Introduction to Mathematical Language Processing: Informal Proofs, Word Problems, and Supporting Tasks
abstract
Abstract Automating discovery in mathematics and science will require sophisticated methods of information extraction and abstract reasoning, including models that can convincingly process relationships between mathematical elements and natural language, to produce problem solutions of real-world value. We analyze mathematical language processing methods across five strategic sub-areas (identifier-definition extraction, formula retrieval, natural language premise selection, math word problem solving, and informal theorem proving) from recent years, highlighting prevailing methodologies, existing limitations, overarching trends, and promising avenues for future research.
Jordan Meadows, André Freitas
Trans. Assoc. Comput. Linguistics2
2022 Hybrid Autoregressive Inference for Scalable Multi-Hop Explanation Regeneration
abstract
Regenerating natural language explanations in the scientific domain has been proposed as a benchmark to evaluate complex multi-hop and explainable inference. In this context, large language models can achieve state-of-the-art performance when employed as cross-encoder architectures and fine-tuned on human-annotated explanations. However, while much attention has been devoted to the quality of the explanations, the problem of performing inference efficiently is largely under studied. Cross-encoders, in fact, are intrinsically not scalable, possessing limited applicability to real-world scenarios that require inference on massive facts banks. To enable complex multi-hop reasoning at scale, this paper focuses on bi-encoder architectures, investigating the problem of scientific explanation regeneration at the intersection of dense and sparse models. Specifically, we present SCAR (for Scalable Autoregressive Inference), a hybrid framework that iteratively combines a Transformer-based bi-encoder with a sparse model of explanatory power, designed to leverage explicit inference patterns in the explanations. Our experiments demonstrate that the hybrid framework significantly outperforms previous sparse models, achieving performance comparable with that of state-of-the-art cross-encoders while being approx 50 times faster and scalable to corpora of millions of facts. Further analyses on semantic drift and multi-hop question answering reveal that the proposed hybridisation boosts the quality of the most challenging explanations, contributing to improved performance on downstream inference tasks.
Marco Valentino, Mokanarangan Thayaparan, Deborah Ferreira, André Freitas
AAAI4
2022 Case-Based Abductive Natural Language Inference
abstract
Most of the contemporary approaches for multi-hop Natural Language Inference (NLI) construct explanations considering each test case in isolation. However, this paradigm is known to suffer from semantic drift, a phenomenon that causes the construction of spurious explanations leading to wrong conclusions. In contrast, this paper proposes an abductive framework for multi-hop NLI exploring the retrieve-reuse-refine paradigm in Case-Based Reasoning (CBR). Specifically, we present Case-Based Abductive Natural Language Inference (CB-ANLI), a model that addresses unseen inference problems by analogical transfer of prior explanations from similar examples. We empirically evaluate the abductive framework on commonsense and scientific question answering tasks, demonstrating that CB-ANLI can be effectively integrated with sparse and dense pre-trained encoders to improve multi-hop inference, or adopted as an evidence retriever for Transformers. Moreover, an empirical analysis of semantic drift reveals that the CBR paradigm boosts the quality of the most challenging explanations, a feature that has a direct impact on robustness and accuracy in downstream inference tasks.
Marco Valentino, Mokanarangan Thayaparan, André Freitas
COLING3
2022 Why Scholars Are Diagramming Neural Network Models
Guy Marshall, Caroline Jay, André Freitas
Diagrams3
2022 Voyager: Data Discovery and Integration for Onboarding in Data Science
Alex Teodor Bogatu, Norman W. Paton, Mark Douthwaite, André Freitas
EDBT4
2022 PhysNLU: A Language Resource for Evaluating Natural Language Understanding and Explanation Coherence in Physics
abstract
In order for language models to aid physics research, they must first encode representations of mathematical and natural language discourse which lead to coherent explanations, with correct ordering and relevance of statements. We present a collection of datasets developed to evaluate the performance of language models in this regard, which measure capabilities with respect to sentence ordering, position, section prediction, and discourse coherence. Analysis of the data reveals the classes of arguments and sub-disciplines which are most common in physics discourse, as well as the sentence-level frequency of equations and expressions. We present baselines that demonstrate how contemporary language models are challenged by coherence related tasks in physics, even when trained on mathematical natural language objectives.
Jordan Meadows, André Freitas
LREC3
2022 Text Classification and Prediction in the Legal Domain
abstract
We present a case study on the application of text classification and legal judgment prediction for flight compensation. We combine transformer-based classification models to classify responses from airlines and incorporate text data with other data types to predict a legal claim being successful. Our experimental evaluations show that our models achieve consistent and significant improvements over baselines and even outperformed human prediction when predicting a claim being successful. These models were integrated into an existing claim management system, providing substantial productivity gains for handling the case lifecycle, currently supporting several thousands of monthly processes.
Minh-Quoc Nghiem, Paul Baylis, André Freitas, Sophia Ananiadou
LREC3
2022 Symmetry-induced Disentanglement on Graphs
abstract
Learning disentangled representations is important for unraveling the underlying complex interactions between latent generative factors. Disentanglement has been formalized using a symmetry-centric notion for unstructured spaces, however, graphs have eluded a similarly rigorous treatment. We fill this gap with a new notion of conditional symmetry for disentanglement, and leverage tools from Lie algebras to encode graph properties into subgroups using suitable adaptations of generative models such as Variational Autoencoders. Unlike existing works on disentanglement, the proposed models segregate the latent space into uncoupled and entangled parts. Experiments on synthetic and real datasets suggest that these models can learn effective disengaged representations, and improve performance on downstream tasks such as few-shot classification and molecular generation.
Giangiacomo Mercatali, André Freitas, Vikas Garg 0001
NeurIPS2
2022 A Survey of Text Games for Reinforcement Learning Informed by Natural Language
abstract
Abstract Reinforcement Learning has shown success in a number of complex virtual environments. However, many challenges still exist towards solving problems with natural language as a core component. Interactive Fiction Games (or Text Games) are one such problem type that offer a set of safe, partially observable environments where natural language is required as part of the Reinforcement Learning solution. Therefore, this survey’s aim is to assist in the development of new Text Game problem settings and solutions for Reinforcement Learning informed by natural language. Specifically, this survey: 1) introduces the challenges in Text Game Reinforcement Learning problems, 2) outlines the generation tools for rendering Text Games and the subsequent environments generated, and 3) compares the agent architectures currently applied to provide a systematic review of benchmark methodologies and opportunities for future researchers.
Philip Osborne, Heido Nõmm, André Freitas
Trans. Assoc. Comput. Linguistics3
2022 Diff-Explainer: Differentiable Convex Optimization for Explainable Multi-hop Inference
abstract
Abstract This paper presents Diff-Explainer, the first hybrid framework for explainable multi-hop inference that integrates explicit constraints with neural architectures through differentiable convex optimization. Specifically, Diff- Explainer allows for the fine-tuning of neural representations within a constrained optimization framework to answer and explain multi-hop questions in natural language. To demonstrate the efficacy of the hybrid framework, we combine existing ILP-based solvers for multi-hop Question Answering (QA) with Transformer-based representations. An extensive empirical evaluation on scientific and commonsense QA tasks demonstrates that the integration of explicit constraints in a end-to-end differentiable framework can significantly improve the performance of non- differentiable ILP solvers (8.91%–13.3%). Moreover, additional analysis reveals that Diff-Explainer is able to achieve strong performance when compared to standalone Transformers and previous multi-hop approaches while still providing structured explanations in support of its predictions.
Mokanarangan Thayaparan, Marco Valentino, Deborah Ferreira, Julia Rozanova, André Freitas
Trans. Assoc. Comput. Linguistics5
2021 Understanding Scholarly Neural Network System Diagrams Through Application of VisDNA
Guy Marshall, Caroline Jay, André Freitas
Diagrams3
2021 Structuralist Analysis for Neural Network System Diagrams
Guy Marshall, Caroline Jay, André Freitas
Diagrams3
2021 Number and Quality of Diagrams in Scholarly Publications is Associated with Number of Citations
Guy Marshall, Caroline Jay, André Freitas
Diagrams3
2021 STAR: Cross-modal [STA]tement [R]epresentation for selecting relevant mathematical premises
abstract
Mathematical statements written in natural language are usually composed of two different modalities: mathematical elements and natural language.These two modalities have several distinct linguistic and semantic properties.State-of-the-art representation techniques have demonstrated an inability in capturing such an entangled style of discourse.In this work, we propose STAR, a model that uses crossmodal attention to learn how to represent mathematical text for the task of Natural Language Premise Selection.This task uses conjectures written in both natural and mathematical language to recommend premises that most likely will be relevant to prove a particular statement.We found that STAR not only outperforms baselines that do not distinguish between natural language and mathematical elements, but it also achieves better performance than state-ofthe-art models.
Deborah Ferreira, André Freitas
EACL2
2021 Unification-based Reconstruction of Multi-hop Explanations for Science Questions
abstract
This paper presents a novel framework for reconstructing multi-hop explanations in science Question Answering (QA).While existing approaches for multi-hop reasoning build explanations considering each question in isolation, we propose a method to leverage explanatory patterns emerging in a corpus of scientific explanations.Specifically, the framework ranks a set of atomic facts by integrating lexical relevance with the notion of unification power, estimated analysing explanations for similar questions in the corpus.An extensive evaluation is performed on the Worldtree corpus, integrating k-NN clustering and Information Retrieval (IR) techniques.We present the following conclusions: (1) The proposed method achieves results competitive with Transformers, yet being orders of magnitude faster, a feature that makes it scalable to large explanatory corpora (2) The unificationbased mechanism has a key role in reducing semantic drift, contributing to the reconstruction of many hops explanations (6 or more facts) and the ranking of complex inference facts (+12.0Mean Average Precision) (3) Crucially, the constructed explanations can support downstream QA models, improving the accuracy of BERT by up to 10% overall.
Marco Valentino, Mokanarangan Thayaparan, André Freitas
EACL3
2021 Natural Language Inference over Tables: Enabling Explainable Data Exploration on Data Lakes
Mario Ramirez, Alex Teodor Bogatu, Norman W. Paton, André Freitas
ESWC4
2021 Cost-effective Variational Active Entity Resolution
abstract
Accurately identifying different representations of the same real-world entity is an integral part of data cleaning and many methods have been proposed to accomplish it. The challenges of this entity resolution task that demand so much research attention are often rooted in the task-specificity and user-dependence of the process. Adopting deep learning techniques has the potential to lessen these challenges. In this paper, we set out to devise an entity resolution method that builds on the robustness conferred by deep autoencoders to reduce human-involvement costs. Specifically, we reduce the cost of training deep entity resolution models by performing unsupervised representation learning. This unveils a transferability property of the resulting model that can further reduce the cost of applying the approach to new datasets by means of transfer learning. Finally, we reduce the cost of labeling training data through an active learning approach that builds on the properties conferred by the use of deep autoencoders. Empirical evaluation confirms the accomplishment of our cost-reduction desideratum, while achieving comparable effectiveness with state-of-the-art alternatives.
Alex Teodor Bogatu, Norman W. Paton, Mark Douthwaite, Stuart Davie, André Freitas
ICDE5
2021 What's Your Value of Travel Time? Collecting Traveler-Centered Mobility Data via Crowdsourcing
Cristian Consonni, Silvia Basile, Matteo Manca, Ludovico Boratto, André Freitas, Tatiana Kovacikova, Ghadir Pourhashem, Yannick Cornet
ICWSM5
2020 Premise Selection in Natural Language Mathematical Texts
abstract
The discovery of supporting evidence for addressing complex mathematical problems is a semantically challenging task, which is still unexplored in the field of natural language processing for mathematical text.The natural language premise selection task consists in using conjectures written in both natural language and mathematical formulae to recommend premises that most likely will be useful to prove a particular statement.We propose an approach to solve this task as a link prediction problem, using Deep Convolutional Graph Neural Networks.This paper also analyses how different baselines perform in this task and shows that a graph structure can provide higher F1-score, especially when considering multi-hop premise selection.
Deborah Ferreira, André Freitas
ACL2
2020 SKG4J 2020: 1st International Workshop on Semantic and Knowledge Graph Advances for Journalism
abstract
SKG4J targeted contributions at the interface between Artificial Intelligence, Data Management and its implications for journalistic practice. The first version of the workshop accepted three submissions with topics emphasising the complementary requirements for delivering realistic journalistic knowledge extraction/management platforms.
Tareq Al-Moslmi, Raphaël Troncy, André Freitas, Davide Ceolin, Abdullatif Abolohom
CIKM3
2020 Natural Language Premise Selection: Finding Supporting Statements for Mathematical Text
abstract
Mathematical text is written using a combination of words and mathematical expressions. This combination, along with a specific way of structuring sentences makes it challenging for state-of-art NLP tools to understand and reason on top of mathematical discourse. In this work, we propose a new NLP task, the natural premise selection, which is used to retrieve supporting definitions and supporting propositions that are useful for generating an informal mathematical proof for a particular statement. We also make available a dataset, NL-PS, which can be used to evaluate different approaches for the natural premise selection task. Using different baselines, we demonstrate the underlying interpretation challenges associated with the task.
Deborah Ferreira, André Freitas
LREC2
2020 A Framework for Evaluation of Machine Reading Comprehension Gold Standards
abstract
Machine Reading Comprehension (MRC) is the task of answering a question over a paragraph of text. While neural MRC systems gain popularity and achieve noticeable performance, issues are being raised with the methodology used to establish their performance, particularly concerning the data design of gold standards that are used to evaluate them. There is but a limited understanding of the challenges present in this data, which makes it hard to draw comparisons and formulate reliable hypotheses. As a first step towards alleviating the problem, this paper proposes a unifying framework to systematically investigate the present linguistic features, required reasoning and background knowledge and factual correctness on one hand, and the presence of lexical cues as a lower bound for the requirement of understanding on the other hand. We propose a qualitative annotation schema for the first and a set of approximative metrics for the latter. In a first application of the framework, we analyse modern MRC gold standards and present our findings: the absence of features that contribute towards lexical ambiguity, the varying factual correctness of the expected answers and the presence of lexical cues, all of which potentially lower the reading comprehension complexity and quality of the evaluation data.
Viktor Schlegel, Marco Valentino, André Freitas, Goran Nenadic, Riza Theresa Batista-Navarro
LREC3
2020 A User-centred Analysis of Explanations for a Multi-component Semantic Parser
Juliano Sales, André Freitas, Siegfried Handschuh
NLDB2
2019 Exploring Knowledge Graphs in an Interpretable Composite Approach for Text Entailment
abstract
Recognizing textual entailment is a key task for many semantic applications, such as Question Answering, Text Summarization, and Information Extraction, among others. Entailment scenarios can range from a simple syntactic variation to more complex semantic relationships between pieces of text, but most approaches try a one-size-fits-all solution that usually favors some scenario to the detriment of another. We propose a composite approach for recognizing text entailment which analyzes the entailment pair to decide whether it must be resolved syntactically or semantically. We also make the answer interpretable: whenever an entailment is solved semantically, we explore a knowledge base composed of structured lexical definitions to generate natural language humanlike justifications, explaining the semantic relationship holding between the pieces of text. Besides outperforming wellestablished entailment algorithms, our composite approach gives an important step towards Explainable AI, using world knowledge to make the semantic reasoning process explicit and understandable.
Vivian Dos Santos Silva, André Freitas, Siegfried Handschuh
AAAI2
2019 Transforming Complex Sentences into a Semantic Hierarchy
abstract
We present an approach for recursively splitting and rephrasing complex English sentences into a novel semantic hierarchy of simplified sentences, with each of them presenting a more regular structure that may facilitate a wide variety of artificial intelligence tasks, such as machine translation (MT) or information extraction (IE).Using a set of hand-crafted transformation rules, input sentences are recursively transformed into a twolayered hierarchical representation in the form of core sentences and accompanying contexts that are linked via rhetorical relations.In this way, the semantic relationship of the decomposed constituents is preserved in the output, maintaining its interpretability for downstream applications.Both a thorough manual analysis and automatic evaluation across three datasets from two different domains demonstrate that the proposed syntactic simplification approach outperforms the state of the art in structural text simplification.Moreover, an extrinsic evaluation shows that when applying our framework as a preprocessing step the performance of state-of-the-art Open IE systems can be improved by up to 346% in precision and 52% in recall.To enable reproducible research, all code is provided online.
Christina Niklaus, Matthias Cetto, André Freitas, Siegfried Handschuh
ACL (1)3
2019 Identifying and Explaining Discriminative Attributes
abstract
Armins Stepanjans, André Freitas. Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP). 2019.
Armins Stepanjans, André Freitas
EMNLP/IJCNLP (1)2
2019 DisSim: A Discourse-Aware Syntactic Text Simplification Framework for English and German
abstract
We introduce DisSim, a discourse-aware sentence splitting framework for English and German whose goal is to transform syntactically complex sentences into an intermediate representation that presents a simple and more regular structure which is easier to process for downstream semantic applications. For this purpose, we turn input sentences into a two-layered semantic hierarchy in the form of core facts and accompanying contexts, while identifying the rhetorical relations that hold between them. In that way, we preserve the coherence structure of the input and, hence, its interpretability for downstream tasks.
Christina Niklaus, Matthias Cetto, André Freitas, Siegfried Handschuh
INLG3
2019 MinWikiSplit: A Sentence Splitting Corpus with Minimal Propositions
abstract
We compiled a new sentence splitting corpus that is composed of 203K pairs of aligned complex source and simplified target sentences.Contrary to previously proposed text simplification corpora, which contain only a small number of split examples, we present a dataset where each input sentence is broken down into a set of minimal propositions, i.e. a sequence of sound, self-contained utterances with each of them presenting a minimal semantic unit that cannot be further decomposed into meaningful propositions.This corpus is useful for developing sentence splitting approaches that learn how to transform sentences with a complex linguistic structure into a fine-grained representation of short sentences that present a simple and more regular structure which is easier to process for downstream applications and thus facilitates and improves their performance.
Christina Niklaus, André Freitas, Siegfried Handschuh
INLG2
2019 Vajra: step-by-step programming with natural language
abstract
Building natural language programming systems that are geared towards end-users requires the abstraction of formalisms inherently introduced by programming languages, capturing the intent of natural language inputs and mapping it to existing programming language constructs.
Viktor Schlegel, Benedikt Lang, Siegfried Handschuh, André Freitas
IUI4
2018 Recognizing and Justifying Text Entailment Through Distributional Navigation on Definition Graphs
abstract
Text entailment, the task of determining whether a piece of text logically follows from another piece of text, has become an important component for many natural language processing tasks, such as question answering and information retrieval. For entailments requiring world knowledge, most systems still work as a "black box," providing a yes/no answer that doesn't explain the reasoning behind it. We propose an interpretable text entailment approach that, given a structured definition graph, uses a navigation algorithm based on distributional semantic models to find a path in the graph which links text and hypothesis. If such path is found, it is used to provide a human-readable justification explaining why the entailment holds. Experiments show that the proposed approach present results comparable to some well-established entailment algorithms, while also meeting Explainable AI requirements, supplying clear explanations which allow the inference model interpretation.
Vivian Dos Santos Silva, Siegfried Handschuh, André Freitas
AAAI3
2018 Graphene: Semantically-Linked Propositions in Open Information Extraction
abstract
We present an Open Information Extraction (IE) approach that uses a two-layered transformation stage consisting of a clausal disembedding layer and a phrasal disembedding layer, together with rhetorical relation identification. In that way, we convert sentences that present a complex linguistic structure into simplified, syntactically sound sentences, from which we can extract propositions that are represented in a two-layered hierarchy in the form of core relational tuples and accompanying contextual information which are semantically linked via rhetorical relations. In a comparative evaluation, we demonstrate that our reference implementation Graphene outperforms state-of-the-art Open IE systems in the construction of correct n-ary predicate-argument structures. Moreover, we show that existing Open IE approaches can benefit from the transformation process of our framework.
Matthias Cetto, Christina Niklaus, André Freitas, Siegfried Handschuh
COLING3
2018 A Survey on Open Information Extraction
abstract
We provide a detailed overview of the various approaches that were proposed to date to solve the task of Open Information Extraction. We present the major challenges that such systems face, show the evolution of the suggested approaches over time and depict the specific issues they address. In addition, we provide a critique of the commonly applied evaluation procedures for assessing the performance of Open IE systems and highlight some directions for future work.
Christina Niklaus, Matthias Cetto, André Freitas, Siegfried Handschuh
COLING3
2018 SemR-11: A Multi-Lingual Gold-Standard for Semantic Similarity and Relatedness for Eleven Languages
Siamak Barzegar, Brian Davis 0001, Manel Zarrouk, Siegfried Handschuh, André Freitas
LREC5
2018 The SSIX Corpora: Three Gold Standard Corpora for Sentiment Analysis in English, Spanish and German Financial Microblogs
Thomas Gaillat, Manel Zarrouk, André Freitas, Brian Davis 0001
LREC3
2018 A Multilingual Test Collection for the Semantic Search of Entity Categories
Juliano Sales, Siamak Barzegar, Wellington Franco, Bernhard Bermeitinger, Brian Davis 0001, André Freitas, Siegfried Handschuh
LREC7
2018 Indra: A Word Embedding and Semantic Relatedness Server
Juliano Sales, Leonardo Souza, Siamak Barzegar, Brian Davis 0001, André Freitas, Siegfried Handschuh
LREC5
2018 Building a Knowledge Graph from Natural Language Definitions for Interpretable Text Entailment Recognition
Vivian Dos Santos Silva, André Freitas, Siegfried Handschuh
LREC2
2018 Classification of composite semantic relations by a distributional-relational model
abstract
Different semantic interpretation tasks such as text entailment and question answering require the classification of semantic relations between terms or entities within text. However, in most cases, it is not possible to assign a direct semantic relation between entities/terms. This paper proposes an approach for composite semantic relation classification using one or more relations between entities/term mentions, extending the traditional semantic relation classification task . The proposed model is different from existing approaches which typically use machine learning models built over lexical and distributional word vector features in that is uses a combination of a large commonsense knowledge base of binary relations , a distributional navigational algorithm and sequence classification to provide a solution for the composite semantic relation classification problem. The proposed approach outperformed existing baselines with regard to F1-score, Accuracy, Precision and Recall.
Siamak Barzegar, Brian Davis 0001, Siegfried Handschuh, André Freitas
Data Knowl. Eng.4
2017 Composite Semantic Relation Classification
Siamak Barzegar, André Freitas, Siegfried Handschuh, Brian Davis 0001
NLDB2
2016 Semantic Relatedness for All (Languages): A Comparative Analysis of Multilingual Semantic Relatedness Using Machine Translation
André Freitas, Siamak Barzegar, Juliano Sales, Siegfried Handschuh, Brian Davis 0001
EKAW1
2016 Word Tagging with Foundational Ontology Classes: Extending the WordNet-DOLCE Mapping to Verbs
Vivian Dos Santos Silva, André Freitas, Siegfried Handschuh
EKAW2
2016 Determining Data Relevance Using Semantic Types and Graphical Interpretation Cues
Eduardo Haruo Kamioka, André Freitas, Frederico Tommasi Caroli, Siegfried Handschuh
IDA2
2016 NNBlocks: A Deep Learning Framework for Computational Linguistics Neural Network Models
Frederico Tommasi Caroli, André Freitas, João C. P. da Silva, Siegfried Handschuh
LREC2
2016 Preface
Chris Biemann, André Freitas, Siegfried Handschuh, Elisabeth Métais, Farid Meziane
Data Knowl. Eng.2
2015 Extending inner-ear anatomical concepts in the Foundational Model of Anatomy (FMA) ontology
abstract
The inner ear is physically inaccessible in living humans, which leads to unique difficulties in studying its normal function and pathology as in other human organs. Recently, biosimulation model has gained a significant attention to understand the exact causative factors that give rise to impairment in human organs. However, to build a biosimulation model for human organ concepts and their topological relationships from multiple and semantically overlapping domains such as biology, anatomy, geometrical, mathematical, physical models are required. In this paper, we focus on modelling the inner-ear macro anatomical concepts and their topological relationships. We extended the Foundational Model of Anatomy (FMA) ontology to cover micro-level version of human inner-ear anatomy where connection between simulating tissues, liquids, soft tissues and connecting adjacent (e.g. hair cells, perilymph) parts studied in detail, included and implemented.
Yasar Khan, Muntazir Mehdi, Alokkumar Jha, Saleem Raza, André Freitas, Marggie Jones, Ratnesh Sahay
BIBE5
2015 DINFRA: A One Stop Shop for Computing Multilingual Semantic Relatedness
abstract
This demonstration presents an infrastructure for computing multilingual semantic relatedness and correlation for twelve natural languages by using three distributional semantic models (DSMs). Our demonsrator - DInfra (Distributional Infrastructure) provides researchers and developers with a highly useful platform for processing large-scale corpora and conducting experiments with distributional semantics. We integrate several multilingual DSMs in our webservice so end user can obtain a result without worrying about the complexities involved in building DSMs. Our webservice allows the users to have easy access to a wide range of comparisons of DSMs with different parameters. In addition, users can configure and access DSM parameters using a easy to use API.
Siamak Barzegar, Juliano Sales, André Freitas, Siegfried Handschuh, Brian Davis 0001
SIGIR3
2015 Linse: A Distributional Semantics Entity Search Engine
abstract
Entering 'Football Players from United States' when searching for 'American Footballers' is an example of vocabulary mismatch, which occurs when different words are used to express the same concepts. In order to address this phenomenon for entity search targeting descriptors for complex categories, we propose a compositional-distributional semantics entity search engine, which extracts semantic and commonsense knowledge from large-scale corpora to address the vocabulary gap between query and data.
Juliano Sales, André Freitas, Siegfried Handschuh, Brian Davis 0001
SIGIR2
2015 Approximate and selective reasoning on knowledge graphs: A distributional semantics approach
André Freitas, João C. P. da Silva, Edward Curry, Paul Buitelaar
Data Knowl. Eng.1
2014 Natural language queries over heterogeneous linked data graphs: a distributional-compositional semantics approach
abstract
The demand to access large amounts of heterogeneous structured data is emerging as a trend for many users and applications. However, the effort involved in querying heterogeneous and distributed third-party databases can create major barriers for data consumers. At the core of this problem is the semantic gap between the way users express their information needs and the representation of the data. This work aims to provide a natural language interface and an associated semantic index to support an increased level of vocabulary independency for queries over Linked Data/Semantic Web datasets, using a distributional-compositional semantics approach. Distributional semantics focuses on the automatic construction of a semantic model based on the statistical distribution of co-occurring words in large-scale texts. The proposed query model targets the following features: (i) a principled semantic approximation approach with low adaptation effort (independent from manually created resources such as ontologies, thesauri or dictionaries), (ii) comprehensive semantic matching supported by the inclusion of large volumes of distributional (unstructured) commonsense knowledge into the semantic approximation process and (iii) expressive natural language queries. The approach is evaluated using natural language queries on an open domain dataset and achieved avg. recall=0.81, mean avg. precision=0.62 and mean reciprocal rank=0.49.
André Freitas, Edward Curry
IUI1
2014 A Distributional Semantics Approach for Selective Reasoning on Commonsense Graph Knowledge Bases
André Freitas, João C. P. da Silva, Edward Curry, Paul Buitelaar
NLDB1
2014 On the Semantic Representation and Extraction of Complex Category Descriptors
André Freitas, Rafael Vieira, Edward Curry, Danilo S. Carvalho, João C. P. da Silva
NLDB1
2013 Towards a semantic representation for multi-scale finite element biosimulation experiments
abstract
Biosimulation researchers use a variety of models, tools and languages for capturing and processing different aspects of biological processes. However, current modeling methods do not capture the underlying semantics of the biosimulation models sufficiently to support building, reusing, composing and merging complex biosimulation models originating from diverse experiments. In this paper, we propose an ontology based and multi-layered biosimulation model to facilitate researchers to share, integrate and collaborate their knowledge bases at Web scale. In particular, we investigate the semantic biosimulation model under the context of the multi-scale finite element (FE) modelling of the inner-ear. The proposed ontology-based biosimulation model will provide a homogenized and standardized access to the shared, semantically integrated and harmonized datasets for clinical data (histological data, micro-CT images of the cochlea, pathological data) and inner ear FE simulation models. The work presented in this paper is analyzed and designed as part of the SIFEM EU project.
André Freitas, Marggie Jones, Kartik Asooja, Christos Bellos, Stephen J. Elliott, Stefan Stenfelt, Panagiotis Hasapis, Christos Georgousopoulos, Torsten Marquardt, Nenad Filipovic, Stefan Decker, Ratnesh Sahay
BIBE1
2013 Answering natural language queries over linked data graphs: a distributional semantics approach
abstract
This paper demonstrates Treo, a natural language query mechanism for Linked Data graphs. The approach uses a distributional semantic vector space model to semantically match user query terms with data, supporting vocabulary-independent (or schema-agnostic) queries over structured data.
André Freitas, Fabrício Firmino de Faria, Seán O'Riain, Edward Curry
SIGIR1
2013 Querying linked data graphs using semantic relatedness: A vocabulary independent approach
André Freitas, João Gabriel Oliveira, Seán O'Riain, João C. P. da Silva, Edward Curry
Data Knowl. Eng.1
2011 Querying Linked Data Using Semantic Relatedness: A Vocabulary Independent Approach
André Freitas, João Gabriel Oliveira, Seán O'Riain, Edward Curry, João C. P. da Silva
NLDB1
2011 Treo: Best-Effort Natural Language Queries over Linked Data
André Freitas, João Gabriel Oliveira, Seán O'Riain, Edward Curry, João C. P. da Silva
NLDB1
2011 W3P: Building an OPM based provenance model for the Web
André Freitas, Tomás Knap, Seán O'Riain, Edward Curry
Future Gener. Comput. Syst.1