Mehrnoosh Sadrzadeh

dblp:39/3325 · also Mehrnouche Sadrzadeh · DBLP profile ↗
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23ranked-venue papers
4as first author
4since 2021 · last 2025
0000-0002-5863-7835ORCID · verified

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

Theory of computation · 12 · 4 first-author · 1 since 2021Artificial intelligence and machine learning · 8 · 1 since 2021Graphics, computer vision, multimedia, augmented reality and games · 3 · 2 since 2021
YearPublicationVenuePosition
2025 Extracting structure from an LLM - how to improve on surprisal-based models of Human Language Processing
abstract
Prediction and reanalysis are considered two key processes that underly humans’ capacity to comprehend language in real time. Computational models capture it using Large Language Models (LLMs) and a statistical measure known as ‘surprisal’. Despite successes of LLMs, surprisal-based models face challenges when it comes to sentences requiring reanalysis due to pervasive temporary structural ambiguities, such as garden path sentences. We ask whether structural information can be extracted from LLM’s and develop a model that integrates it with their learnt statistics. When applied to a dataset of garden path sentences, the model achieved a significantly higher correlation with human reading times than surprisal. It also provided a better prediction of the garden path effect and could distinguish between sentence types with different levels of difficulty.
Daphne Wang, Mehrnoosh Sadrzadeh, Milos Stanojevic, Wing-Yee Chow, Richard Breheny
COLING2
2024 Lambek Calculus with Banged Atoms for Parasitic Gaps
Mehrnoosh Sadrzadeh, Lutz Straßburger
WoLLIC1
2023 Semantic and Lexical Token Based Vectors Improve Precision of Recommendations for TV Programmes
abstract
Advances in the digitalisation of data have led to large archives of content in media companies. These archives include multimodal data and metadata associated with each media programme. Relating content across different mediums of data and metadata has thus become an emergent challenge, with applications to popular domains such as programme recommendation. In this paper, we worked with combinations of content similarity measures computed from the distances between different forms of textual data obtained from subtitle files and metadata obtained from the genres of programmes. The different forms of textual representations we considered were neural semantic and topic vectors, and a weighted Jaccard distance encoding lexical token rareness. The late fusion combination of these four distances provided the best recommendation results. For a weekly dataset of 145 TV programmes, it increased the precision of the genre-based recommendations by 5.76%. In a monthly dataset of 906 programmes, it achieved an increase of 1.5%. This combination was more efficient than one with audio and video files.
Taner Cagali, Hadi Wazni, Saba Nazir, Mehrnoosh Sadrzadeh, Chris Newell
ISM4
2021 Enhancing Personalised Recommendations with the Use of Multimodal Information
abstract
Whenever we watch a TV show or movie, we process a substantial amount of information that is conveyed to us via various multimedia mediums, in particular: visual, textual, and audio. These data signify distinctive properties that aid in creating a unique motion picture experience. In effort to not only produce a more personalised recommender system, but also tackle the problem of popularity bias, we develop a system that incorporates the use of multimodal information. Specifically, we investigate the correlation between features that are extracted using state of the art techniques and deep learning models from visual characteristics, audio patterns and subtitles. The framework is evaluated on a dataset comprising of 145 BBC TV programmes against genre and user baselines. We demonstrate that personalised recommendations can not only be improved with the use of multimodal information, but also outperform genre and user-based models in terms of diversity, whilst maintaining matching levels of accuracy.
Taner Cagali, Mehrnoosh Sadrzadeh, Chris Newell
ISM2
2020 Representation Learning for Type-Driven Composition
abstract
This paper is about learning word representations using grammatical type information. We use the syntactic types of Combinatory Categorial Grammar to develop multilinear representations, i.e. maps with n arguments, for words with different functional types. The multilinear maps of words compose with each other to form sentence representations. We extend the skipgram algorithm from vectors to multi- linear maps to learn these representations and instantiate it on unary and binary maps for transitive verbs. These are evaluated on verb and sentence similarity and disambiguation tasks and a subset of the SICK relatedness dataset. Our model performs better than previous type- driven models and is competitive with state of the art representation learning methods such as BERT and neural sentence encoders.
Gijs Wijnholds, Mehrnoosh Sadrzadeh, Stephen Clark
CoNLL2
2020 Audiovisual, Genre, Neural and Topical Textual Embeddings for TV Programme Content Representation
abstract
TV programmes have their contents described by multiple means: textual subtitles, audiovisual files, and metadata such as genres. In order to represent these contents, we develop vectorial representations for their low-level multimodal features, group them with simple clustering techniques, and combine them using middle and late fusion. For textual features, we use LSI and Doc2Vec neural embeddings; for audio, MFCC's and Bags of Audio Words; for visual, SIFT, and Bags of Visual Words. We apply our model to a dataset of BBC TV programmes and use a standard recommender and pairwise similarity matrices of content vectors to estimate viewers' behaviours. The late fusion of genre, audio and video vectors with both of the textual embeddings significantly increase the precision and diversity of the results.
Saba Nazir, Taner Cagali, Mehrnoosh Sadrzadeh, Chris Newell
ISM3
2019 Principles of Natural Language, Logic, and Tensor Semantics (Invited Paper)
abstract
Residuated monoids model the structure of sentences. Vectors provide meaning representations for words. A functorial mapping between the two is obtained by lifting the vectors to tensors. The resulting sentence representations solve similarity, disambiguation and entailment tasks.
Mehrnoosh Sadrzadeh
CALCO1
2019 A generalised quantifier theory of natural language in categorical compositional distributional semantics with bialgebras
abstract
Abstract Categorical compositional distributional semantics is a model of natural language; it combines the statistical vector space models of words with the compositional models of grammar. We formalise in this model the generalised quantifier theory of natural language, due to Barwise and Cooper. The underlying setting is a compact closed category with bialgebras. We start from a generative grammar formalisation and develop an abstract categorical compositional semantics for it, and then instantiate the abstract setting to sets and relations and to finite-dimensional vector spaces and linear maps. We prove the equivalence of the relational instantiation to the truth theoretic semantics of generalised quantifiers. The vector space instantiation formalises the statistical usages of words and enables us to, for the first time, reason about quantified phrases and sentences compositionally in distributional semantics.
Jules Hedges, Mehrnoosh Sadrzadeh
Math. Struct. Comput. Sci.2
2017 Non-commutative Logic for Compositional Distributional Semantics
Karin Cvetko-Vah, Mehrnoosh Sadrzadeh, Dimitri Kartsaklis, Benjamin Blundell
WoLLIC2
2016 Distributional Inclusion Hypothesis for Tensor-based Composition
abstract
According to the distributional inclusion hypothesis, entailment between words can be measured via the feature inclusions of their distributional vectors. In recent work, we showed how this hypothesis can be extended from words to phrases and sentences in the setting of compositional distributional semantics. This paper focuses on inclusion properties of tensors; its main contribution is a theoretical and experimental analysis of how feature inclusion works in different concrete models of verb tensors. We present results for relational, Frobenius, projective, and holistic methods and compare them to the simple vector addition, multiplication, min, and max models. The degrees of entailment thus obtained are evaluated via a variety of existing word-based measures, such as Weed’s and Clarke’s, KL-divergence, APinc, balAPinc, and two of our previously proposed metrics at the phrase/sentence level. We perform experiments on three entailment datasets, investigating which version of tensor-based composition achieves the highest performance when combined with the sentence-level measures.
Dimitri Kartsaklis, Mehrnoosh Sadrzadeh
COLING2
2016 The Frobenius anatomy of word meanings II: possessive relative pronouns
abstract
Within the categorical compositional distributional model of meaning, we provide semantic interpretations for the subject and object roles of the possessive relative pronoun ‘whose’. This is done in terms of Frobenius algebras over compact closed categories. These algebras and their diagrammatic language expose how meanings of words in relative clauses interact with each other. We show how our interpretation is related to Montague-style semantics and provide a truth-theoretic interpretation. We also show how vector spaces provide a concrete interpretation and provide preliminary corpus-based experimental evidence. In a prequel to this article, we used similar methods and dealt with the case of subject and object relative pronouns.
Mehrnoosh Sadrzadeh, Stephen Clark, Bob Coecke
J. Log. Comput.1
2015 Open System Categorical Quantum Semantics in Natural Language Processing
abstract
Originally inspired by categorical quantum mechanics (Abramsky and Coecke, LiCS'04), the categorical compositional distributional model of natural language meaning of Coecke, Sadrzadeh and Clark provides a conceptually motivated procedure to compute the meaning of a sentence, given its grammatical structure within a Lambek pregroup and a vectorial representation of the meaning of its parts. Moreover, just like CQM allows for varying the model in which we interpret quantum axioms, one can also vary the model in which we interpret word meaning. In this paper we show that further developments in categorical quantum mechanics are relevant to natural language processing too. Firstly, Selinger's CPM-construction allows for explicitly taking into account lexical ambiguity and distinguishing between the two inherently different notions of homonymy and polysemy. In terms of the model in which we interpret word meaning, this means a passage from the vector space model to density matrices. Despite this change of model, standard empirical methods for comparing meanings can be easily adopted, which we demonstrate by a small-scale experiment on real-world data. Secondly, commutative classical structures as well as their non-commutative counterparts that arise in the image of the CPM-construction allow for encoding relative pronouns, verbs and adjectives, and finally, iteration of the CPM-construction, something that has no counterpart in the quantum realm, enables one to accommodate both entailment and ambiguity.
Robin Piedeleu, Dimitri Kartsaklis, Bob Coecke, Mehrnoosh Sadrzadeh
CALCO4
2015 Concrete Models and Empirical Evaluations for the Categorical Compositional Distributional Model of Meaning
abstract
Modeling compositional meaning for sentences using empirical distributional methods has been a challenge for computational linguists. The categorical model of Clark, Coecke, and Sadrzadeh (2008) and Coecke, Sadrzadeh, and Clark (2010) provides a solution by unifying a categorial grammar and a distributional model of meaning. It takes into account syntactic relations during semantic vector composition operations. But the setting is abstract: It has not been evaluated on empirical data and applied to any language tasks. We generate concrete models for this setting by developing algorithms to construct tensors and linear maps and instantiate the abstract parameters using empirical data. We then evaluate our concrete models against several experiments, both existing and new, based on measuring how well models align with human judgments in a paraphrase detection task. Our results show the implementation of this general abstract framework to perform on par with or outperform other leading models in these experiments.1
Edward Grefenstette, Mehrnoosh Sadrzadeh
Comput. Linguistics2
2014 Evaluating Neural Word Representations in Tensor-Based Compositional Settings
abstract
We provide a comparative study between neural word representations and traditional vector spaces based on cooccurrence counts, in a number of compositional tasks.We use three different semantic spaces and implement seven tensor-based compositional models, which we then test (together with simpler additive and multiplicative approaches) in tasks involving verb disambiguation and sentence similarity.To check their scalability, we additionally evaluate the spaces using simple compositional methods on larger-scale tasks with less constrained language: paraphrase detection and dialogue act tagging.In the more constrained tasks, co-occurrence vectors are competitive, although choice of compositional method is important; on the largerscale tasks, they are outperformed by neural word embeddings, which show robust, stable performance across the tasks.
Dmitrijs Milajevs, Dimitri Kartsaklis, Mehrnoosh Sadrzadeh, Matthew Purver
EMNLP3
2014 Algebraic semantics and model completeness for Intuitionistic Public Announcement Logic
Alessandra Palmigiano, Mehrnoosh Sadrzadeh
Ann. Pure Appl. Log.3
2013 Separating Disambiguation from Composition in Distributional Semantics
Dimitri Kartsaklis, Mehrnoosh Sadrzadeh, Stephen G. Pulman
CoNLL2
2013 Prior Disambiguation of Word Tensors for Constructing Sentence Vectors
abstract
Recent work has shown that compositionaldistributional models using element-wise operations on contextual word vectors benefit from the introduction of a prior disambiguation step.The purpose of this paper is to generalise these ideas to tensor-based models, where relational words such as verbs and adjectives are represented by linear maps (higher order tensors) acting on a number of arguments (vectors).We propose disambiguation algorithms for a number of tensor-based models, which we then test on a variety of tasks.The results show that disambiguation can provide better compositional representation even for the case of tensor-based models.Furthermore, we confirm previous findings regarding the positive effect of disambiguation on vector mixture models, and we compare the effectiveness of the two approaches.
Dimitri Kartsaklis, Mehrnoosh Sadrzadeh
EMNLP2
2013 Lambek vs. Lambek: Functorial vector space semantics and string diagrams for Lambek calculus
Bob Coecke, Edward Grefenstette, Mehrnoosh Sadrzadeh
Ann. Pure Appl. Log.3
2013 The Frobenius anatomy of word meanings I: subject and object relative pronouns
abstract
This paper develops a compositional vector-based semantics of subject and object relative pronouns within a categorical framework. Frobenius algebras are used to formalise the operations required to model the semantics of relative pronouns, including passing information between the relative clause and the modified noun phrase, as well as copying, combining, and discarding parts of the relative clause. We develop two instantiations of the abstract semantics, one based on a truth-theoretic approach and one based on corpus statistics.
Mehrnoosh Sadrzadeh, Stephen Clark, Bob Coecke
J. Log. Comput.1
2013 Algebra, proof theory and applications for an intuitionistic logic of propositions, actions and adjoint modal operators
abstract
We develop a cut-free nested sequent calculus as basis for a proof search procedure for an intuitionistic modal logic of actions and propositions. The actions act on propositions via a dynamic modality (theweakest preconditionof program logics), whose left adjoint we refer to as “update” (thestrongest postcondition). The logic has agent-indexed adjoint pairs of epistemic modalities: the left adjoints encode agents' uncertainties and the right adjoints encode their beliefs. The rules for the “update” modality encode learning as a result of discarding uncertainty. We prove admissibility ofCut, and hence the soundness and completeness of the logic with respect to an algebraic semantics. We interpret the logic on epistemic scenarios that consist of honest and dishonest communication actions, add assumption rules to encode them, and prove that the calculus with the assumption rules still has the admissibility results. We apply the calculus to encode (and allow reasoning about) the classic epistemic puzzles ofdirty children(a.k.a. “muddy children”) anddrinking logiciansand some versions with dishonesty or noise; we also give an application where the actions are movements of a robot rather than announcements.
Roy Dyckhoff, Mehrnoosh Sadrzadeh, Julien Truffaut
ACM Trans. Comput. Log.2
2011 Experimental Support for a Categorical Compositional Distributional Model of Meaning
Edward Grefenstette, Mehrnoosh Sadrzadeh
EMNLP2
2007 Coalgebraic Epistemic Update Without Change of Model
Corina Cîrstea, Mehrnoosh Sadrzadeh
CALCO2
2007 Epistemic Actions as Resources
abstract
We provide an algebraic semantics together with a sound and complete sequent calculus for information update due to epistemic actions. This semantics is flexible enough to accommodate incomplete as well as wrong information e.g. due to secrecy and deceit, as well as nested knowledge. We give a purely algebraic treatment of the muddy children puzzle, which moreover extends to situations where the children are allowed to lie and cheat. Epistemic actions, that is, information exchanges between agents A,B,…∈A⁠, are modeled as elements of a quantale. The quantale (Q,⋁,•) acts on an underlying Q-right module(M,⋁) of epistemic propositions and facts. The epistemic content is encoded by appearance maps, one pair fMA:M→M and fQA:Q→Q of (lax) morphisms for each agent A∈A⁠, which preserve the module and quantale structure respectively. By adjunction, they give rise to epistemic modalities, capturing the agents' knowledge on propositions and actions. The module action is epistemic update and gives rise to dynamic modalities—cf. weakest precondition. This model subsumes the crucial fragment of Baltag, Moss and Solecki's dynamic epistemic logic, abstracting it in a constructive fashion while introducing resource-sensitive structure on the epistemic actions.
Alexandru Baltag, Bob Coecke, Mehrnoosh Sadrzadeh
J. Log. Comput.3