VLDB 2026 Research / reviewers in the wild / expert
Sahan Bulathwela
dblp:254/2062
· DBLP profile ↗
17ranked-venue papers
6as first author
13since 2021 · last 2026
0000-0002-5878-2143ORCID · corroborated
Domains — the database's venue-derived domains; a paper can count in several
Applied, interdisciplinary, general and emerging computing · 10 · 3 first-author · 9 since 2021Human-computer interaction and ubiquitous computing · 9 · 1 first-author · 9 since 2021Artificial intelligence and machine learning · 6 · 3 first-author · 3 since 2021Graphics, computer vision, multimedia, augmented reality and games · 5 · 2 first-author · 3 since 2021Databases, data management, data science and information retrieval · 2 · 1 first-author · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | AgentGraph: Trace-to-Graph Platform for Interactive Analysis and Robustness Testing in Agentic AI SystemsabstractModern Agentic AI systems plan, reason, and act across multiple steps, creating execution patterns that are difficult to interpret. Existing observability platforms track prompt I/O and operational metrics but require manual inspection of traces to reconstruct structure and reasoning. We present AgentGraph, which converts execution logs into interactive knowledge graphs and actionable insights. Nodes represent agents, tasks, tools, data inputs/outputs, and humans, while typed edges capture relations such as inputs consumed, tasks delegated or sequenced, tools required or used, outputs produced and delivered, and interventions from agents or humans. Each graph element links to its exact trace span, ensuring verifiability. Building on this representation, AgentGraph enables two analyses: qualitative trace-grounded failure detection and optimisation recommendations, and quantitative robustness evaluation via perturbation testing and causal attribution. Zekun Wu 0003, Seonglae Cho, Cristian E. Muñoz Villalobos, Theo King, Umar Mohammed, Emre Kazim, María Pérez-Ortiz 0001, Sahan Bulathwela, Adriano S. Koshiyama |
AAAI | 8 |
| 2026 | Catching The Correct Answer Trap: Characterising AI Tutor Blind Spots When Analysing Student Reasoning
Moiz Imran, Sahan Bulathwela |
AIED (5) | 2 |
| 2026 | Gaze to Insight: A Scalable AI Approach for Detecting Gaze Behaviours in Face-To-Face Collaborative Learning
Junyuan Liang, Qi Zhou 0011, Sahan Bulathwela, Mutlu Cukurova |
AIED (1) | 3 |
| 2026 | Mix and Match: Context Pairing for Scalable Topic-Controlled Educational Summarisation
Nathikan Yodthapa, Thanapong Intharah, Sahan Bulathwela |
AIED (3) | 3 |
| 2026 | Examining Student Interactions with a Pedagogical AI-Assistant for Essay Writing and their Impact on Students' Writing Quality
Wicaksono Febriantoro, Qi Zhou 0011, Wannapon Suraworachet, Sahan Bulathwela, Andrea Gauthier, Eva Millán, Mutlu Cukurova |
LAK | 4 |
| 2026 | Scaffolding Reshapes Dialogic Engagement in Collaborative Problem Solving: Comparative Analysis of Two ApproachesabstractAbstract. Supporting learners during Collaborative Problem Solving (CPS) is a necessity. Existing studies have compared scaffolds with maximal and minimal instructional support by studying their effects on learning and behaviour. However, our understanding of how such scaffolds could differently shape the distribution of individual engagement and behaviours across different CPS phases remains limited. This study applied Heterogeneous Interaction Network Analysis (HINA) and Sequential Pattern Mining (SPM) to uncover the structural effects of scaffolding on different phases of the CPS process among 78 students aged 14 - 15 years in authentic educational settings. Students with the maximal scaffold demonstrated higher dialogic engagement across more phases than those with the minimal scaffold. However, they demonstrated extensive scripting behaviours across the phases, evidencing the presence of overscripting. Although students with the minimal scaffold demonstrated more problem solving behaviours and fewer scripting behaviours across the phases, they repeated particular behaviours in multiple phases and progressed more to socialising behaviours. In both scaffold conditions, problem solving behaviours rarely progressed to other problem solving behaviours. The paper discusses the implications for scaffold design and teaching practice of CPS, and highlights the distinct yet complementary value of HINA and SPM approaches to investigate students’ learning processes during CPS. Kester Wong, Shihui Feng, Sahan Bulathwela, Mutlu Cukurova |
LAK | 3 |
| 2025 | Rethinking the Potential of Multimodality in Collaborative Problem Solving Diagnosis with Large Language Models
Kester Wong, Bin Wu 0025, Sahan Bulathwela, Mutlu Cukurova |
AIED (2) | 3 |
| 2025 | A Novel Approach to Scalable and Automatic Topic-Controlled Question Generation in Education
Mutlu Cukurova, Sahan Bulathwela |
LAK | 3 |
| 2024 | A Toolbox for Modelling Engagement with Educational VideosabstractWith the advancement and utility of Artificial Intelligence (AI), personalising education to a global population could be a cornerstone of new educational systems in the future. This work presents the PEEKC dataset and the TrueLearn Python library, which contains a dataset and a series of online learner state models that are essential to facilitate research on learner engagement modelling. TrueLearn family of models was designed following the "open learner" concept, using humanly-intuitive user representations. This family of scalable, online models also help end-users visualise the learner models, which may in the future facilitate user interaction with their models/recommenders. The extensive documentation and coding examples make the library highly accessible to both machine learning developers and educational data mining and learning analytics practitioners. The experiments show the utility of both the dataset and the library with predictive performance significantly exceeding comparative baseline models. The dataset contains a large amount of AI-related educational videos, which are of interest for building and validating AI-specific educational recommenders. Yuxiang Qiu, Karim Djemili, Denis Elezi, Aaneel Shalman, María Pérez-Ortiz 0001, Emine Yilmaz, John Shawe-Taylor, Sahan Bulathwela |
AAAI | 8 |
| 2023 | Pre-training with Scientific Text Improves Educational Question Generation (Student Abstract)abstractWith the boom of digital educational materials and scalable e-learning systems, the potential for realising AI-assisted personalised learning has skyrocketed. In this landscape, the automatic generation of educational questions will play a key role, enabling scalable self-assessment when a global population is manoeuvring their personalised learning journeys. We develop EduQG, a novel educational question generation model built by adapting a large language model. Our initial experiments demonstrate that EduQG can produce superior educational questions by pre-training on scientific text. Hamze Muse, Sahan Bulathwela, Emine Yilmaz |
AAAI | 2 |
| 2023 | Scalable Educational Question Generation with Pre-trained Language Models
Sahan Bulathwela, Hamze Muse, Emine Yilmaz |
AIED | 1 |
| 2022 | Watch Less and Uncover More: Could Navigation Tools Help Users Search and Explore Videos?abstractPrior research has shown how ‘content preview tools’ improve speed and accuracy of user relevance judgements across different information retrieval tasks. This paper describes a novel user interface tool, the Content Flow Bar, designed to allow users to quickly identify relevant fragments within informational videos to facilitate browsing, through a cognitively augmented form of navigation. It achieves this by providing semantic “snippets” that enable the user to rapidly scan through video content. The tool provides visually-appealing pop-ups that appear in a time series bar at the bottom of each video, allowing to see in advance and at a glance how topics evolve in the content. We conducted a user study to evaluate how the tool changes the users search experience in video retrieval, as well as how it supports exploration and information seeking. The user questionnaire revealed that participants found the Content Flow Bar helpful and enjoyable for finding relevant information in videos. The interaction logs of the user study, where participants interacted with the tool for completing two informational tasks, showed that it holds promise for enhancing discoverability of content both across and within videos. This discovered potential could leverage a new generation of navigation tools in search and information retrieval. María Pérez-Ortiz 0001, Sahan Bulathwela, Claire Dormann, Meghana Verma, Stefan Kreitmayer, Richard Noss, John Shawe-Taylor, Yvonne Rogers, Emine Yilmaz |
CHIIR | 2 |
| 2022 | Can Population-based Engagement Improve Personalisation? A Novel Dataset and Experiments
Sahan Bulathwela, Meghana Verma, María Pérez-Ortiz 0001, Emine Yilmaz, John Shawe-Taylor |
EDM | 1 |
| 2020 | Towards an Integrative Educational Recommender for Lifelong Learners (Student Abstract)abstractOne of the most ambitious use cases of computer-assisted learning is to build a recommendation system for lifelong learning. Most recommender algorithms exploit similarities between content and users, overseeing the necessity to leverage sensible learning trajectories for the learner. Lifelong learning thus presents unique challenges, requiring scalable and transparent models that can account for learner knowledge and content novelty simultaneously, while also retaining accurate learners representations for long periods of time. We attempt to build a novel educational recommender, that relies on an integrative approach combining multiple drivers of learners engagement. Our first step towards this goal is TrueLearn, which models content novelty and background knowledge of learners and achieves promising performance while retaining a human interpretable learner model. Sahan Bulathwela, María Pérez-Ortiz 0001, Emine Yilmaz, John Shawe-Taylor |
AAAI | 1 |
| 2020 | TrueLearn: A Family of Bayesian Algorithms to Match Lifelong Learners to Open Educational ResourcesabstractThe recent advances in computer-assisted learning systems and the availability of open educational resources today promise a pathway to providing cost-efficient high-quality education to large masses of learners. One of the most ambitious use cases of computer-assisted learning is to build a lifelong learning recommendation system. Unlike short-term courses, lifelong learning presents unique challenges, requiring sophisticated recommendation models that account for a wide range of factors such as background knowledge of learners or novelty of the material while effectively maintaining knowledge states of masses of learners for significantly longer periods of time (ideally, a lifetime). This work presents the foundations towards building a dynamic, scalable and transparent recommendation system for education, modelling learner's knowledge from implicit data in the form of engagement with open educational resources. We i) use a text ontology based on Wikipedia to automatically extract knowledge components of educational resources and, ii) propose a set of online Bayesian strategies inspired by the well-known areas of item response theory and knowledge tracing. Our proposal, TrueLearn, focuses on recommendations for which the learner has enough background knowledge (so they are able to understand and learn from the material), and the material has enough novelty that would help the learner improve their knowledge about the subject and keep them engaged. We further construct a large open educational video lectures dataset and test the performance of the proposed algorithms, which show clear promise towards building an effective educational recommendation system. Sahan Bulathwela, María Pérez-Ortiz 0001, Emine Yilmaz, John Shawe-Taylor |
AAAI | 1 |
| 2020 | Predicting Engagement in Video Lectures
Sahan Bulathwela, María Pérez-Ortiz 0001, Aldo Lipani, Emine Yilmaz, John Shawe-Taylor |
EDM | 1 |
| 2020 | SUM'20: State-based User ModellingabstractCapturing and effectively utilising user states and goals is becoming a timely challenge for successfully leveraging intelligent and usercentric systems in differentweb search and data mining applications. Examples of such systems are conversational agents, intelligent assistants, educational and contextual information retrieval systems, recommender/match-making systems and advertising systems, all of which rely on identifying the user state in order to provide the most relevant information and assist users in achieving their goals. There has been, however, limited work towards building such state-aware intelligent learning mechanisms. Hence, devising information systems that can keep track of the user's state has been listed as one of the grand challenges to be tackled in the next few years [1]. It is thus timely to organize a workshop that re-visits the problem of designing and evaluating state-aware and user-centric systems, ensuring that the community (spanning academic and industrial backgrounds) works together to tackle these challenges. Sahan Bulathwela, María Pérez-Ortiz 0001, Rishabh Mehrotra, Davor Orlic, Colin de la Higuera, John Shawe-Taylor, Emine Yilmaz |
WSDM | 1 |