I'm looking for doctoral students, postdocs and research fellows to work with on Bayesian Workflow. Flexible starting time

Aki Vehtari@avehtari.bsky.social · 2mo ago

ELLIS Institute Finland PostDoc and doctoral student call is open (DL September 21, 2026). You can apply also to work with me on computational methods for Bayesian workflows www.ellisinstitute.fi/postdoc-and-...

Now #hiring: postdocs and PhD students in AI & machine learning research. Deadline Sept. 21, 2026. - Cutting-edge computational resources like @lumi-supercomputer.eu - Close collaboration with @ellis.eu network - Ambitious, high-impact projects across Finland www.ellisinstitute.fi/postdoc-and-...

We need reviewers for our submission to the Journal of Open Source Education. Our resource focuses on MCMC convergence, model checking, comparison, etc all powered by ArviZ. This is the issue where you can volunteer: github.com/openjournals...

[PRE REVIEW]: Exploratory Analysis of Bayesian Models · Issue #289 · openjournals/jose-reviews

Submitting author: @aloctavodia (Osvaldo Martin) Repository: https://github.com/arviz-devs/EABM Branch with paper.md (empty if default branch): Version: v0.2.0 Editor: Pending Reviewers: Pending Ma...

github.com

The StanCon2026 conference on probabilistic programming for Bayes in Uppsala is over. Very positive experience with interesting talks, a large poster session and social activities. And some HMC updates to modernize the Bayesian Songbook! All talks are on YouTube: youtube.com/playlist?lis...

StanCon 2026 Uppsala - YouTube

youtube.com

ArviZ 1.3 has been released! 🎉 python.arviz.org/en/latest Check out the highlights 👇

ArviZ: Exploratory analysis of Bayesian models

Rank ECDF Diagnostic along the posterior’s KDE using plot_rank_dist https://arviz-plots.readthedocs.io/en/stable/api/generated/arviz_plots.plot_rank_dist.html Forest Plot with ESS using plot_forest...

python.arviz.org

1/ Great chat with Alex Andorra aka @learnbayesstats.bsky.social about efficient inference, from amortized to surrogate-based approaches and a variety of related topics (prior-fitted networks, foundation models for inference and planning, etc.), many of which are neural processes in a trenchcoat.

Pierre-Simon Laplace@learnbayesstats.bsky.social · 3mo ago

Episode 161 is out 🎧 In which @lacerbi.bsky.social explains why transformers are secretly neural processes, how his Amortized Conditioning Engine unifies inference and prediction, and why "amortize everything" needed a rethink. 🔗 learnbayesstats.com/episode/161-... #bayesian #bayesianinference

Look what was waiting on my desk this morning! It's so great to finally see #BayesianWorkflow in print.

@aloctavodia.bsky.social has been porting Bayesian Workflow book avehtari.github.io/Bayesian-Wor... case studies to Python using CmdStanPy, numpyro, ArviZ, Bambi, and kulprit arviz-devs.github.io/bayesian-wor... He is working on porting the rest of the case studies, too

Bayesian Workflow book: Case studies in Python – Bayesian Workflow case studies in Python

arviz-devs.github.io

More details about the Bayesian Workflow book and case studies now available on the book web site avehtari.github.io/Bayesian-Wor... (but you still need to wait a bit for the book)

Richard McElreath 🐈‍⬛@rmcelreath.bsky.social · 6mo ago

I would have preferred to have the "draw the rest of the owl" meme on the cover, but this will do. Seems like it is on schedule, and we'll leave some typos so you know we didn't write it with AI.

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.

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...

I'm looking for a post-doc to help organize Bayesian Data Analysis course avehtari.github.io/BDA_course_A... (200 students) and to do research on Bayesian workflow users.aalto.fi/~ave/publica... at Aalto www.aalto.fi/en, Finland. Background in Bayes needed. Up to five year contract possible.

arviz-stats exposes two APIs: • Full xarray API (default): intended for end users doing statistical data analysis. • Array-only API (NumPy/SciPy): intended for PPL developers or advanced users, who want diagnostics without xarray as a dependency.

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: a modular and flexible library for exploratory analysis of Bayesian models

Martin et al., (2026). ArviZ: a modular and flexible library for exploratory analysis of Bayesian models. Journal of Open Source Software, 11(119), 9889, https://doi.org/10.21105/joss.09889

joss.theoj.org

ArviZ 1.0 is out! We have refactored it to be more modular, flexible & lightweight. For an overview of the changes, check the migration guide. python.arviz.org/en/stable/us...

If you have been using LOO-PIT, this is a must read for you; "LOO-PIT predictive model checking" by me and @avehtari.bsky.social , doi.org/10.48550/arX.... 1/4

If you have been using LOO-PIT, this is a must read for you! @herman-tesso.bsky.social has done excellent work with this paper! Thanks for @florencebockting.bsky.social and @aloctavodia.bsky.social for getting this to bayesplot and ArviZ. I'll notify when I have my casestudies updated with this

Herman@herman-tesso.bsky.social · 8mo ago

If you have been using LOO-PIT, this is a must read for you; "LOO-PIT predictive model checking" by me and @avehtari.bsky.social , doi.org/10.48550/arX.... 1/4

Bayesian Analysis with Python is part of Packt’s $10 eBook campaign right now. If it’s been on your reading or recommendation list, this could be a good time to grab it, along with many other books too: landing.packtpub.com/data-science...

🔥 StanCon 2026 registration and abstract submission are now open! 🔥 Please spread the word! discourse.mc-stan.org/t/stancon-20...

StanCon 2026 registration and abstract submission is now open

Hi everyone! Registration for StanCon 2026 in Uppsala, Sweden, is now open! You can already register and submit abstracts for contributions. Our first keynote speaker will be announced soon. New thi...

discourse.mc-stan.org

All the material for my Bayesian Data Analysis course is available online, including the lectures, which we re-recorded this fall (some of them by @aloctavodia.bsky.social and Noa Kallioinen while I was on vacation). The video links are listed in the schedule at avehtari.github.io/BDA_course_A...

New projpred (projection predictive variable selection for brms and rstanarm) release 2.10.0. Frank Weber added support for censored observations when using the latent projection (see a vignette mc-stan.org/projpred/art...). @aloctavodia.bsky.social fixed bugs and made the release.

Now I'm also looking for a research software engineer to implement a pile of research results to R packages loo, posterior, bayesplot, projpred, priorsense, brms or/and Python packages ArviZ, Bambi and Kulprit. Apply by email with no specific deadline (see contact info at users.aalto.fi/~ave/)

Aki Vehtari@avehtari.bsky.social · 12mo ago

I'm now also looking for a postdoc with strong Bayesian background and interest in developing Bayesian cross-validation theory, methods and software. Apply by email with no specific deadline (see contact information at users.aalto.fi/~ave/). Others, please share

I'm now also looking for a postdoc with strong Bayesian background and interest in developing Bayesian cross-validation theory, methods and software. Apply by email with no specific deadline (see contact information at users.aalto.fi/~ave/). Others, please share

Aki Vehtari@avehtari.bsky.social · last yr.

I'm looking for a doctoral student with Bayesian background to work on Bayesian workflow and cross-validation (see my publication list users.aalto.fi/~ave/publica... for my recent work) at Aalto University. Apply through the ELLIS PhD program (dl October 31) ellis.eu/news/ellis-p...

"Uncertainty in Bayesian leave-one-out cross-validation based model comparison" with Tuomas Sivula, Asael Alonzo Matamoros, and @mansmag.bsky.social, has been published in Bayesian Analysis doi.org/10.1214/25-B... 🧵 1/

Uncertainty in Bayesian Leave-One-Out Cross-Validation Based Model Comparison

It is useful to estimate the expected predictive performance of models planned to be used for prediction. We focus on leave-one-out cross-validation (LOO-CV), which has become a popular method for estimating predictive performance of Bayesian models. Given two models, we are interested in comparing the predictive performances and associated uncertainty, which can also be used to compute the probability of one model having better predictive performance than the other model. We study the properties of the Bayesian LOO-CV estimator and the related uncertainty quantification for the predictive performance difference, and analyse when a normal approximation of this uncertainty is well calibrated and whether taking into account higher moments could improve the approximation. We provide new results of the properties both theoretically in the linear regression case and empirically for hierarchical linear, latent linear, and spline models and discuss the challenges. We show that problematic cases include: comparing models with similar predictions, misspecified models, and small data. In these cases, there is a weak connection between the distributions of the LOO-CV estimator and its error. We show that that the problematic skewness of the error distribution for the difference, which occurs when the models make similar predictions, does not fade away when the data size grows to infinity in certain situations. Based on the results, we also provide some practical recommendations for the users of Bayesian LOO-CV for comparing predictive performance of models.

doi.org

I got mail! I can’t not wait @vincentab.bsky.social I’ll try to do many of these examples by “hand” (learning by doing).

Interested in Bayesian workflow and cross-validation? Join Aki Vehtari’s group at Aalto University as a PhD student! Apply through the ELLIS PhD program by Oct 31 → ellis.eu/news/ellis-p... Recent work: users.aalto.fi/~ave/publica...

ELLIS PhD Program: Call for Applications 2025

The ELLIS mission is to create a diverse European network that promotes research excellence and advances breakthroughs in AI, as well as a pan-European PhD program to educate the next generation of AI...

ellis.eu

I'm looking for a doctoral student with Bayesian background to work on Bayesian workflow and cross-validation (see my publication list users.aalto.fi/~ave/publica... for my recent work) at Aalto University. Apply through the ELLIS PhD program (dl October 31) ellis.eu/news/ellis-p...

ELLIS PhD Program: Call for Applications 2025

The ELLIS mission is to create a diverse European network that promotes research excellence and advances breakthroughs in AI, as well as a pan-European PhD program to educate the next generation of AI...

ellis.eu

Our faculty is looking for PhD students in artificial intelligence and machine learning! Meet our new Principal Investigators and apply for a PhD position by the end of October: www.ellisinstitute.fi/PIs-2025 All the info about the ELLIS PhD program is below! 👇

ELLIS@ellis.eu · last yr.

🎓 The application portal for the #ELLISPhD Program is open today! Info & link: https://bit.ly/45DSe75

The Pink Book of #MarginalEffects (aka Model to Meaning) ships next week and I've got a backlog of Zoolander memes. Hope you're hungry for some spam in your timeline. #RStats #PyData

Vincent Arel-Bundock@vincentab.bsky.social · last yr.

Whoa—my book is up for pre-order! 𝐌𝐨𝐝𝐞𝐥 𝐭𝐨 𝐌𝐞𝐚𝐧𝐢𝐧𝐠: 𝐇𝐨𝐰 𝐭𝐨 𝐈𝐧𝐭𝐞𝐫𝐩𝐫𝐞𝐭 𝐒𝐭𝐚𝐭 & 𝐌𝐋 𝐌𝐨𝐝𝐞𝐥𝐬 𝐢𝐧 #Rstats 𝐚𝐧𝐝 #PyData The book presents an ultra-simple and powerful workflow to make sense of ± any model you fit The web version will stay free forever and my proceeds go to charity. tinyurl.com/4fk56fc8

Our recent media coverage 🧵👇 with features in @hs.fi, Finland's public broadcaster Yle and the @aalto.fi Keys to Growth series. cc @ellis.eu @okm.fi @csaalto.bsky.social bsky.app/profile/elli...

ELLIS Institute Finland@ellisinstitute.fi · last yr.

How does a small country and a new research institute take on the tech giants in AI? Top international talent, academic freedom and boundary-breaking basic research. Along with Finland's commitment 📈 to 4% of GDP for RDI, we have the makings of big impacts in AI and ML research. (More in Finnish 👇)