New paper out in JOSS:
“ArviZ: a modular and flexible library for exploratory analysis of Bayesian models”
It covers the design principles behind ArviZ and the motivation for the refactoring in 1.0. joss.theoj.org/papers/10.21...
ArviZ 1.0 brings a lot of new plotting functionality.
Check our gallery for a glimpse of what's new: python.arviz.org/projects/plo...
ArviZ now has built-in tools for prior & likelihood sensitivity analysis via power-scaling!
Instead of fitting multiple models with different priors, you fit once and use importance sampling to approximate the effect of perturbing the prior or likelihood.
First tentative draft of huge chapter on bayesian models of cognition for my Cognitive Modeling (in @mc-stan.org )course notes: fusaroli.github.io/AdvancedCogn...
I'll probably need to split it, as I want to add models of sequential update and empirical data 😅
occARU: Bayesian (multispecies) occupancy models for ARU data using @mc-stan.org. Automated recording units (ARUs) like camera traps produce rich time series which warrant going beyond occupancy and focusing on detection rates. 1/n
mhollanders.github.io/occARU/
New Cognitive Modeling in R and @mc-stan.org chapters up: hierarchical modeling and model comparison. Still not satisfied with the text, but I brought the code and concepts up to date (LOO-PIT even, altho' still an info dump).
Comments are welcome!
fusaroli.github.io/AdvancedCogn...
"Efficient Bayesian implementations of capture-recapture models with Stan" by @matthollanders.bsky.social discourse.mc-stan.org/t/bayesian-c...
We are happy to announce the second StanCon 2026 workshop:
🔥 Bayesian Inference for Sparsity-Promoting and Edge-Preserving Priors 🔥
More information on the workshop can be found here:
www.janglaubitz.com/stancon2026
More info on Stancon 2026 in Uppsala can be found here:
www.stancon2026.org
Improved Stan language support in Emacs by Brian Ward discourse.mc-stan.org/t/setting-up... and in Neovim by Andrew Mascioli discourse.mc-stan.org/t/setting-up...
We hare happy to announce the first StanCon workshop:
🔥 Stan for pharmacometrics 🔥
discourse.mc-stan.org/t/stancon-20...
More information on the workshop can be found here:
stan4pmx2026.sciencesconf.org
Figure shows the proportion of successful putts by distance (where we have integrated out the missing distances) and geometrical model 2 (as presented in https://users.aalto.fi/~ave/casestudies/disc_putting/disc_putting.html) based putting probability by distances based on data for top 33 PDGA MPO players.
I've made a geometrical model for disc golf putting with uncertainty in 2D angle and distance control.
Based on the model, the putting angle accuracies of top PDGA MPO and FPO players are about 1° and 1.4°, respectively. See more at users.aalto.fi/~ave/casestu...
Now published in Collabra!
online.ucpress.edu/collabra/art...
Using test data from TwinLife (N=9,980, Culture Fair Test CFT 20-R), we show that Regularised Prediction and Poststratification yields IQ scores that differ by up to 19 IQ points (mean 4.19 pts) from those reported in the CFT 20-R manual
🔥 Last Keynote for StanCon 2026 🔥
We are happy to present Mathew Kay (@mjskay.com) as a keynote at StanCon in Uppsala in August!
More information here:
discourse.mc-stan.org/t/announcing...
@mc-stan.org
my course notes on a bayesian workflow for (single agent) cognitive modeling are now fully revised and online: fusaroli.github.io/AdvancedCogn...
Predictive checks, updating checks, sensitivity analyses and simulation based calibration in @mc-stan.org
Feedback is very welcome!
Kalman filter. It still targets the correct posterior, but can be orders of magnitude more efficient for some widely used models. Other times it is just a little bit more efficient. Open-source Stan implementation (@mc-stan.org) will be on OSF in the afternoon. Preprint: doi.org/10.48550/arX...
Progress bar showing 2800/8000 35% ETA: 4m
Help to test new progress bar in CmdStanR by @josswright.bsky.social, see more at discourse.mc-stan.org/t/help-us-te...
A new blog post!
In which @matterofstats.bsky.social and I estimate our own risk preferences in @mc-stan.org with the hope of best responding to a proper scoring rule.
#EconSky #AFL
jamesblandecon.github.io/posts/2026-0...
Like usual, @mc-stan.org eats this stuff up. 7,000 observations, each with its own corresponding latent variable. Model estimated in a bit over 3 hours with no warnings.
Bayesian joint modelling using @mc-stan.org of wastewater and hospital admissions in the US led by @kaitejohnson9.bsky.social and others at the US CDC
Two days to StanCon 202 oral presentation abstract submission deadline!!!
🔥 StanCon 2026 third keynote announced 🔥
Kaitlyn Johnson,
London School of Hygiene & Tropical Medicine
More information here
discourse.mc-stan.org/t/announcing...
@mc-stan.org
25th February deadline is mainly for oral presentations, and poster submission deadline is 27th May. If you want to present a poster and need confirmation of acceptance earlier, you can submit a poster abstract now and get confirmation by March 25 as for oral presentations.
StanCon 2026 deadline for oral presentations 25th of February! discourse.mc-stan.org/t/stancon-20...
If you have any questions, ask in Stan discourse or contact one of the local organizing committee members
StanCon 20206 International Conferene on Bayesian Inference and Probabilistic Programming 17-21 August, 2026 Uppsala, Sweden
Three weeks time to submit contributed talk abstract to StanCon 2026! You can also submit a poster abstract early, if you need to make early travel plans. There will be travel and accommodation support for students, too!
More information about submitting at www.stancon2026.org/abstracts/
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/
wanna learn about cognitive modeling and love pizza? I am revising my cognitive modeling course notes and could use some feedback (or you might just enjoy learning about cog modeling in R and Stan): fusaroli.github.io/AdvancedCogn...
(only chapter 1-3 are in place, the others will come)
1/9 New blog is live! This is part 2 of a series—last time we looked at the Dunning-Kruger effect, now we are digging in to Implicit vs Explicit attitudes and the Implicit Association Test. To start, of course we need a good meme...
haines-lab.com/post/part-2-...
if you want to know how to compute marginal means from a mixed effects model in brms using rvars, then have I got a supplemental materials document for you pubs.asha.org/doi/10.1044/...
StanCon 2026 is this August 17-21 in Upsala, Sweden 🇸🇪
www.stancon2026.org
⏰ Abstracts for contributed talks are due Feb 25
⏰ Abstracts for posters are due May 27
And just to be clear: Yes, StanCon is my favorite conference to attend!! Can't wait for this one!
![R console output of the posterior summaries:
sumr |> arrange(ess_tail)
# A tibble: 3,986 × 4
variable rhat ess_bulk ess_tail
<chr> <dbl> <dbl> <dbl>
1 gamma[4,9] 1.02 153. 1861.
2 gamma[4,8] 1.02 191. 1921.
3 m[4] 1.02 211. 2336.
4 A[4,5] 1.01 440. 2918.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:udsm6acdtllf76voqzflv4ou/bafkreid5fwo76lqi7rhheijnnql6m4w3x5kvksbigjxf47uhapsh22zzrq)
R console output of the posterior summaries: sumr |> arrange(ess_tail) # A tibble: 3,986 × 4 variable rhat ess_bulk ess_tail <chr> <dbl> <dbl> <dbl> 1 gamma[4,9] 1.02 153. 1861. 2 gamma[4,8] 1.02 191. 1921. 3 m[4] 1.02 211. 2336. 4 A[4,5] 1.01 440. 2918.
Working on a fairly complex model and getting good tail-ESS but poor bulk-ESS values. Seems somewhat counterintuitive at first, but the model has multimodal posterior which likely explains this. @mc-stan.org #Bayesian #mcmc #stan #stats #rstats