Jean-Loup Baer Professor @UWCSE seeking to better understand and empower people through data and computation. Recruiting PhD students and Postdocs
Seattle, WA
Joined January 2012
- Tweets1.6K
- Following1.8K
- Followers5K
- Likes4K
Pinned Tweet
I’m excited to share our new @Nature paper 📝, which provides strong evidence that the walkability of our built environment matters a great deal to our physical activity and health.
Details in thread.🧵
nature.com/articles/s41586-0…
Tim Althoff retweeted
Finding clinical signals in large-scale health sensing data streams is quite challenging. We introduce a biomarker discovery framework that pairs hypothesis generation with adversarial validation to discover rigorous digital biomarkers alongside human experts. Read more: goo.gle/4gavroG
ALT Overview of the Biomarker Discovery Framework. (a) The system ingests time series data from consumer wearables and clinical labs. (b) A closed-loop architecture orchestrates six phases mirroring the human biomarker prioritization lifecycle. (c) An Orchestrator agent decomposes natural-language research directives into execution plans.
Tim Althoff retweeted
We are thrilled with our speakers and panelists and would love to see you participate in the discussion.
clpsych.org/program/
Tim Althoff retweeted
Sense of community is the "glue" that holds online communities together! But what factors affect sense of community online? Come to my talk @icwsm tomorrow morning at 8:30 to learn more! 🧵
Tim Althoff retweeted
MoEs are everywhere, but the design space is confusing: total vs active experts? expert size? shared experts? routing? token dropping?
We train >2000 MoE LMs 🫠 to investigate and bring you:
📄🔪🍰 Slicing and Dicing MoEs
Tl;dr: it's all about expert size and count
[1/9]
Tim Althoff retweeted
📢 New Paper 📢 Self-Improving VLM Judges Without Human Annotations
Reward models & judges are critical for evaluating output quality and alignment with human preferences for VLM training.
Current training approaches typically rely on:
💸 Costly human preference annotations
🔒 Distillation from large closed-source models GPT/Claude (which also use human labels)
😤 Labels that may become obsolete as models advance
We show you can skip all of this with self-generated synthetic data! ✨👀
We're still accepting postdoc applications starting as early as January'26. Focus areas include psychosocial AI simulation and safety, Human-AI collaboration.
Details: docs.google.com/document/d/1…
Tim Althoff retweeted
Large Language Models (LLMs) are increasingly used to simulate human users in interactive settings. However, they often drift from their assigned personas, contradict earlier statements, or abandon role-appropriate behavior. We introduce a framework for evaluating and improving persona consistency in LLM-generated dialogue with multi-turn RL, defining three automatic metrics and validating each against human annotations. More below 👇
Our ability to meaningfully evaluate language models is critical, but challenged in many ways.
Check out @kenqgu's work that finally helps us disentangle "reasoning ability" from "parametric/world knowledge", while allowing for scalable, automated evaluation.
True intelligence = reasoning about new information, not memorized facts.
How can we scalably create benchmarks that are completely novel yet have known answers?
Meet SynthWorlds, an eval & data-gen framework to disentangle reasoning and knowledge⬇️🧵
📄arxiv.org/pdf/2510.24427
Tim Althoff retweeted
True intelligence = reasoning about new information, not memorized facts.
How can we scalably create benchmarks that are completely novel yet have known answers?
Meet SynthWorlds, an eval & data-gen framework to disentangle reasoning and knowledge⬇️🧵
📄arxiv.org/pdf/2510.24427
(please reshare) I'm recruiting multiple PhD students and Postdocs @uwcse @uwnlp
(bdata.uw.edu). Focus areas incl. psychosocial AI simulation and safety, Human-AI collaboration.
PhD: cs.washington.edu/academics/…
Postdocs: docs.google.com/document/d/1…
Tim Althoff retweeted
Need a lab? Moonshots abstracts due this Sat, Oct 25. We’re backing species-level swings in civic discourse, accelerating science, frontline healthcare, and workforce reskilling.
8× $250k seed grants now; then one or more $10M+ multi-year labs to continue the work.
Selection committee members include:
@timalthoff, @davidautor, @chris_bail, @erikbryn, @YejinChoinka, @fchollet, Mariano-Florentino (Tino) Cuéllar, @JeffDean, @ghadfield, @HannaHajishirzi, @bradenjhancock, John Hennessy, @erichorvitz, @JohnJumperSci, @tkalil2050, @zakkohane, @andykonwinski, @tommmitchell, @emollick, Dave Patterson (Chair), @PlevritisLab, @DG_Rand, @ChrisRytting, @YalaTweets, @Diyi_Yang, @james_y_zou
Apply: moonshots.laude.org/
Tim Althoff retweeted
If you're at @ACM_CSCW 🇳🇴, come check out our 🏆honorable mention paper today on Reddit community governance (w/@amyxzh @timalthoff). 4pm in Dovregubben-2! More in thread... 🧵
Tim Althoff retweeted
Calling all impact researchers who want to ship.
We're pumping $10Ms+ funding into AI research that improves society (via civic discourse, accelerating science, frontline healthcare, or workforce reskilling).
This is Laude Moonshots.
Humbled by the program committee we've assembled: @timalthoff, @davidautor, @chris_bail, @erikbryn, @YejinChoinka, @fchollet, Mariano-Florentino (Tino) Cuéllar, @JeffDean, @ghadfield, @HannaHajishirzi, @bradenjhancock, John Hennessy, @erichorvitz, @JohnJumperSci, @tkalil2050, @zakkohane, @andykonwinski, @tommmitchell, @emollick, Dave Patterson (Chair), @PlevritisLab, @DG_Rand, me, @Thom_Wolf, @YalaTweets, @Diyi_Yang, @james_y_zou.
We’re counting down to our first round of Laude Moonshots. It’s energizing to see researchers mobilizing AI for urgent, real-world impact. Abstracts are due October 25. Details: moonshots.laude.org
Tim Althoff retweeted
Some nice coverage of our paper (and award) from ICWSM back in June. Big congrats to Leon his successful first author paper, and big things to @timalthoff and @amyxzh for their support as always!
Allen School researchers receive ICWSM Best Paper Award for analyzing how Reddit rules influence online community outcomes news.cs.washington.edu/2025/…
Tim Althoff retweeted
Allen School researchers receive ICWSM Best Paper Award for analyzing how Reddit rules influence online community outcomes news.cs.washington.edu/2025/…
Tim Althoff retweeted
Congrats again to ugrad student Leon Leibmann and co-authors @galenweld and @timalthoff on best paper award (awarded to a single paper) at @icwsm this year!
Allen School researchers receive ICWSM Best Paper Award for analyzing how Reddit rules influence online community outcomes news.cs.washington.edu/2025/…
Tim Althoff retweeted
ICYMI - our recent @Nature paper leverages a large dataset to show that a city's walkability influences our physical activity and health.
nature.com/articles/s41586-0…
I’m excited to share our new @Nature paper 📝, which provides strong evidence that the walkability of our built environment matters a great deal to our physical activity and health.
Details in thread.🧵
nature.com/articles/s41586-0…
Tim Althoff retweeted
Crunching away on a paper for #CHI2026 about online communities, moderation, or sociolinguistics?
You may be want to check out recent work led by @galenweld on predicting SOVC within subreddits based on the style and structure of conversations.
arxiv.org/abs/2508.08596
Tim Althoff retweeted
Do walkable cities prompt people to take more steps, or do people who want to walk tend to live in more pedestrian-friendly cities?
New research from @timalthoff @uwcse found that highly walkable areas lead to significantly more walking.
More: bit.ly/4lNxFKh
ALT Pedestrians walk along Seattle's waterfront
City planning is a powerful public health tool 🛠️. Investing in sidewalks, parks, and mixed-use zoning is a direct investment in citizens' health, making entire populations healthier. 💚
Huge thanks to my amazing co-authors @iamborisi, Abby King, Jennifer Hicks, Scott Delp, and @jure (representing @uwcse @Stanford @StanfordDeptMed @StanfordNMBL @Nvidia) 🙏