Tim Althoff Profile
Tim Althoff

@timalthoff

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Associate Professor @UWCSE developing computational methods that leverage large-scale behavioral data to improve human well-being. Recruiting PhD students :-)

Seattle, WA
Joined January 2012
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@timalthoff
Tim Althoff
2 hours
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.🧵.
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@timalthoff
Tim Althoff
2 hours
Huge thanks to my amazing co-authors @iamborisi, Abby King, Jennifer Hicks, Scott Delp, and @jure (representing @uwcse @Stanford @StanfordDeptMed @StanfordNMBL @Nvidia) 🙏.
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@grok
Grok
5 days
The most fun image & video creation tool in the world is here. Try it for free in the Grok App.
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@timalthoff
Tim Althoff
2 hours
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. 💚.
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@timalthoff
Tim Althoff
2 hours
So, is it just that active people choose walkable cities? Our data says no. People who moved between similarly walkable cities saw no change in their activity. This suggests that the built environment, not just personal choice, is a central driver. ✅.
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@timalthoff
Tim Althoff
2 hours
In fact, moving to a much more walkable city nearly doubled the chances that a person would meet the national guidelines for physical activity (150 mins of MVPA/week), jumping from 21.5% to 42.5%. This is great news! 🎉.
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@timalthoff
Tim Althoff
2 hours
This isn't just about more steps—it’s about the right kind. Our study shows this extra activity is mostly brisk walking, which is the MVPA doctors recommend to prevent disease. Moving to a highly walkable city can add an hour of this health-boosting activity to a person's week.
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@timalthoff
Tim Althoff
2 hours
This effect is symmetric. People moving to NYC from less walkable places gained ~1,400 steps 🗽. People who moved away from NYC lost ~1,400 steps. This "before and after" picture is powerful evidence that the environment is the key driver of physical activity. 🔄.
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@timalthoff
Tim Althoff
2 hours
The key finding: your city can make you healthier. 🏙️➡️🚶‍♀️ People who moved from a less walkable city to a more walkable one increased their walking by ~1,100 steps a day, on average. That's about 11 minutes of extra walking without even thinking about it! 👟.
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@timalthoff
Tim Althoff
2 hours
To solve this, we ran a massive "natural experiment." We studied smartphone data from 2 million people 🤳, including ~5,000 who moved between 1,609 U.S. cities. This gave us a unique before-and-after picture 📸 of how their physical activity changed with their environment.
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@timalthoff
Tim Althoff
2 hours
The big question we couldn’t yet answer at the time: is it the city that makes people walk more, or do active people just choose to live there? 🤔.
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@timalthoff
Tim Althoff
2 hours
8 years ago, we published a study using smartphone data to understand people's activity globally 🗺️. We found huge differences in daily steps across cities.
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nature.com
Nature - Globally, millions of deaths each year are associated with physical inactivity but our understanding of activity patterns in different populations remains limited owing to a lack of...
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@timalthoff
Tim Althoff
20 hours
RT @a_bricca: These findings provide robust evidence supporting the importance of the built environment in directly improving health-enhanc….
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@timalthoff
Tim Althoff
20 hours
RT @NaturePortfolio: A study in @Nature shows that urban environments that are designed to be easily navigable encourage physical activity.….
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@timalthoff
Tim Althoff
20 hours
RT @EricTopol: A natural experiment provides evidence for promoting moderate-vigorous physical activity: the importance of walkable cities….
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nature.com
Nature - By analysing the smartphone data of 2,112,288 participants, in particular observing and comparing the activity of the same individual in two different environments, we find that increases...
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@timalthoff
Tim Althoff
14 days
RT @GoogleResearch: Let your wearable data "speak" for itself! Introducing SensorLM, a family of sensor-language foundation models trained….
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@timalthoff
Tim Althoff
17 days
RT @HannaHajishirzi: Congratulations to @sewon__min for winning yet another dissertation award, this time, ACL dissertation award. So proud….
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@timalthoff
Tim Althoff
1 month
Most complex tasks feature ill- and underdefined goals, at least initially. Check out @vysrini's paper demonstrating that agents need to do a lot more than follow instructions, incl. refining goals, and balance competing objectives. Current frontier models fail at these tasks.
@vysrini
Vidya Srinivas
1 month
Excited to share our paper, Substance over Style: Evaluating Proactive Conversational Coaching Agents, accepted to ACL 2025 Main Track!. LLMs do well when given clear context up front. But what if that context doesn't exist yet? .(1/5). 🔗Read more:
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@timalthoff
Tim Althoff
1 month
RT @vysrini: Excited to share our paper, Substance over Style: Evaluating Proactive Conversational Coaching Agents, accepted to ACL 2025 Ma….
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