xuan (ɕɥɛn / sh-yen)

frog on the floorrrr
where'd he come from
nobody knows
where he'll goooo

The political effects of X’s feed algorithm - Nature Among users initially on a chronological feed, 7 weeks of exposure to X’s algorithmic feed in 2023 shifted political attitudes and account-following behaviour in a more conservative direction compared...

Check out this recent @nature.com paper reporting a field experiment on X. It shows X's algorithm boosts conservative content and downranks traditional media—shifting users’ views on key issues. Switching to chronological doesn’t reverse the effect. www.nature.com/articles/s41...

A line graph showing NSF grant awards made through 2/27/26 for fiscal year 2026 compared with grant awards for fiscal years 2021-2025.

NSF Update (Awards through 2/27/26)

Directorates to follow

1/10

Wait you did theory of mind for self-driving cars? Very cool!

(Never wanted to work on the perception parts of robotics or AVs, but have worked a lot on and still work on Bayesian inverse planning.)

also just not fun as a vegetarian who tries to avoid killing insects for the most part 😞

just had my first encounter with rice weevils that I recall being aware of, and I am simultaneously upset at the fact that:
- there were bugs suddenly crawling out of my rice
- I have probably already eaten them previously
- apparently this is not especially uncommon with rice bought here
😖

also a cool thing about revisiting this after learning probabilistic programming is that now I could probably write a semantic parser + RSA-style pragmatic disambiguator that implements each of these theories :)

in case people are curious, the diagrams only get more complicated lol

(also according to past Xuan, the homonymic theory is correct)

this prompted me to reread my 1st year college essay on whether proper names w diff. referents are more like indexicals ("I", etc.) vs. homonyms, and I totally forgot I made all these crazy diagrams despite not having taken a philosophy class before

truly doomed to be analytic-philosophy-brained 😅

Also probabilistic programming has its own chapter 😊

Finally bought my first actual copy of "AI: A Modern Approach" (as a reference for the lab) and it's cool to see that assistance games have their own section now!

cc: @dhadfieldmenell.bsky.social

Gladys Mae West obituary: mathematician who pioneered GPS technology She made key contributions to US cold-war science despite facing huge barriers as a Black woman.

No joke: I got angry hate mail today for writing an obituary of a Black woman scientist—because the person felt she did didn’t deserve the recognition.

Which just makes me want to share it again: www.nature.com/articles/d41...

as I'm revising my course materials, I keep stumbling upon cool @mc-stan.org developments.

Current favorites:
1. your model has funnels and you exhausted reparametrization ideas: metric = "dense_e" makes your HMC learn about covariance btw parameters. Sloooow, but effective!
1/

Incidentally I think one strong piece of evidence for the theory that (many) emotional expressions and their associated concepts are learned rather than innate is the ever-expanding set of Slack/Discord/etc emoji reactions.

Full paper / original thread here:

bsky.app/profile/yyan...

Value computations underpin flexible emotion expression Yi Yang Teoh & Cendri A. Hutcherson Communications Psychology volume 3, Article number: 169 (2025) Abstract Emotion expressions constitute a vital channel for communication, coordination and connection with others, but despite such valuable functions, people sometimes engage in expressive suppression or substitution (expressing emotions they do not genuinely feel). Yet, how exactly do people decide when and what to express? To answer this question, we developed a computational model that casts emotion expressions as value-based communicative decisions. Our model reveals that while people (N = 254) indeed tended to suppress expressions of anger towards others in anticipation of potential social costs as past work theorizes, they also engaged in other nuanced forms of expressive regulation, especially when their reputation was at stake. Most strikingly, people selectively exaggerated/suppressed expressions of happiness when others made more/less equitable choices, seemingly to communicate stronger normative preferences for fairness than they privately held. Together, these findings yield insights into how people regulate their emotion expressions, providing a mechanistic and unified account of the different expressive behaviors people flexibly engage in to navigate their complex social interactions with others.

I was curious whether people have developed "rational models" of emotional expression, and it looks like there's a very recent paper on the topic!

By @yyangteoh.bsky.social and @cendripetalfrce.bsky.social.

Value computations underpin flexible emotion expression - Communications Psychology People do not always express the emotions they feel truthfully. Computational modelling reveals that people flexibly regulate their emotion expressions by balancing their value as a communicative sign...

Happy to finally see this paper (w/ @cendripetalfrce.bsky.social) out now @commspsychol.nature.com
We built a computational framework to show people flexibly balance communicative benefits against social costs when deciding whether and how to express their emotions. www.nature.com/articles/s44...

One of the earlier feminist lessons I had to learn in life was how to cut off friendships with sexual abusers (+ their friend groups).

I unfortunately had to learn this in high school, but with all the Epstein stuff coming out, I'm reminded that most haven't learned this at all.

example is adapted from @julianje.bsky.social's paper haha

in which my students explain the context-sensitivity of social roles and norms 😅

a phd

other people: reading the Innovator's Dilemma bc they want to run a successful start-up

me rn: reading the Innovator's Dilemma bc I'm a historical materialist 🌹

I'd like to say something about ICE, but what if they review my social media history the next time I apply for an ESTA, decide my wokeness will destroy America, and shoot me 10 times dead when I next cross the border? Can't really blame them 🤷🏻‍♀️

watched Ed Feigenbaum talk at #AAAI2026 and apparently the way he got into AI research was kinda like mine --- got bored as an elec. eng. freshman, took a class on "Ideas & Social Change", which led to studying with Herbert Simon on Math. Models in the Social Sciences, and hence, AI!

Wow *none* of the top-10 Google results properly explain the slang etymology of "chopped" (unattractive / ugly), so I feel obliged to note that it almost certainly comes from ballroom + drag culture, where being "chopped" means being cut from a performance category.

Then again, I suppose this is the generation for whom "chopped" is simply part of the vernacular.

Just walked past a NUS student dance group doing warmups to a ballroom / vogue track, Ha Dub and all, and frankly I'm confused how the gayest possible dance music has become this globally mainstream.

Apparently the LHS is by a Singapore-based company so I apologize on behalf of my country

I regret to report that the AI ads have spread to HK airport.