Joseph Y. Halpern was a pioneering computer scientist whose work reshaped how we reason about knowledge, causality, uncertainty, and multi-agent systems. His contributions were foundational and far-reaching — spanning logic, probability, game theory, and distributed computing.
Joe last joined us at KR 2024 in Hanoi, as an invited speaker on the panel "Great Ideas from KR: drawing on the past to shape the future." He received the Ray Reiter Best Paper Prize at KR 2012, among many other high-impact contributions.
This one-day workshop brings together researchers whose work touches Joe's legacy — to celebrate his ideas and carry them forward. It will be held on July 19, 2026 in Lisbon, Portugal, as part of FLoC 2026, co-located with KR 2026.
Submissions are now closed. Register for the conference.
We are compiling a collection of messages, photos, and short videos from those who knew him, which will be presented to his family as a gift.
Please submit your material using this
Google Form
A few quick guidelines for your submission:
- Videos: If you submit a video, please try to keep it between 30 and 60 seconds and record it in landscape (horizontal) mode.
- File Sizes: The form accepts photos up to 100MB and videos up to 1GB. If you need to submit a larger file, please upload it to Google Drive (or another cloud service) and share the accessible link in the written message prompt on the form.
- Deadline: Please submit your memories by the 10th of July.
Accepted Research Papers
- Operationalising Relative Causal Knowledge: Backbone Identifiability from Private Reports
- Salient Preference Dynamics: A Model of Attention-Driven Preference Change
- Lessons from the Past for the Future of Robotics
- Proof-theoretic approach to representable qualitative probabilities
- Cheap Talk Games with Dempster-Shafer Priors
- Answer Set Programming for Actual Causality: The Role of Negations
- Causality, Harm, and Elections
- Computing Actual Causes for Neural Network Predictions under Structured Causal Inputs
Invited Talks, Research and Personal
- Dov Samet
- Ron van der Meyden
- Moshe Vardi
- Hector Geffner
- Adam Bjorndahl
- Daphne Koller
- Yoav Shoham
- Gerhard Lakemeyer
- Brian Logan
- Natasha Alechina
- Orna Kupferman
- Hans van Ditmarsch
- Yoram Moses
- Johan van Benthem
- Ittai Abraham
- Sainyam Galhotra
All deadlines are AoE — Anywhere on Earth (UTC−12).
| Paper submission deadline | |
| Notification of acceptance | |
| Early registration deadline | June 1, 2026 |
| Workshop | July 19, 2026 |
- Sander Beckers University College London, UK
- Hana Chockler King's College London, UK
- Esra Erdem Sabancı University, Türkiye
- Ivan Geffner Utrecht University, Netherlands
- Fangzhen Lin Hong Kong University of Science and Technology, Hong Kong
- Evan Piermont Royal Holloway, University of London, UK