Ed Merkle
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edgarmerkle.bsky.social
Ed Merkle
@edgarmerkle.bsky.social
680 followers 130 following 35 posts
quantitative psychologist, open source enthusiast, recently working on R package blavaan
Posts Replies Media Videos
Reposted by Ed Merkle
charlesdriver.bsky.social
ctsem has a GUI now -- visual, SEM-like spec, fit & diagnostics for hierarchical discrete or continuous time state space models (i.e., DSEM's).
github.com/cdriveraus/c...

State-space (process + measurement) and individual difference views shown.

Ideas welcome! Workshop @saa2026.bsky.social
July 28, 2026 at 2:47 PM
Reposted by Ed Merkle
avehtari.bsky.social
Stan embedded Laplace was a long project and happy that it's finally released. We are not competing with INLA and TMB software, as they are orders of magnitude faster and scale better with data size for models that you can implement with them 1/
mc-stan.org MC Stan @mc-stan.org · May 19
CmdStan 2.39 has been released!
- embedded Laplace approximation
- new yule_simon distribution
- gamma_lccdf more stable
- optimization convergence status in output
- length-1 tuples

See more at blog.mc-stan.org/2026/05/19/r...
May 20, 2026 at 8:54 AM
Reposted by Ed Merkle
chimeracoder.bsky.social
do yourself a favor and search for something like "Pokémon" (something that was big in 2000 and is still big now).

then do the same on Google

It's amazing how much the Internet has changed - in many ways for the worse - and we don't even realize it
 Kevin Smokler @weegee.bsky.social · May 1
OldaVista is a search engine model designed for searching "the old internet" i.e. website hosted on Geocities, AOL Hometown, Xoom and on blocks of stone written in cuneiform.
Old'aVista
A search engine for OLD websites hosted in services like Geocities, Angelfire, Xoom, AOL, Tripod and so on!
oldavista.com
May 1, 2026 at 3:33 AM
edgarmerkle.bsky.social
Here is a newly-accepted paper (at Methodology) discussing issues and unexpected behavior of WAIC and PSIS-LOO when applied to psychometric models. It is based on situations that I initially thought were bugs in blavaan, but they turned out not to be.

(download link is at the bottom of the page)
Nuances of information criteria for Bayesian psychometric models [Author Accepted Manuscript] | PsychArchives
PsychArchives is a disciplinary repository for psychological science and neighboring disciplines.
doi.org
April 29, 2026 at 4:40 PM
Reposted by Ed Merkle
paperposterbot.bsky.social
arXiv📈🤖
Approximate Bayesian Inference for Structural Equation Models using Integrated Nested Laplace Approximations
By Jamil, Rue
Markov chain Monte Carlo (MCMC) methods remain the mainstay of Bayesian estimation of structural equation models (SEM); however they often incur a high computational cost. We present a bespoke approximate Bayesian approach to SEM, drawing on ideas from the integrated nested Laplace approximation (INLA; Rue et al., 2009, J. R. Stat. Soc. Series B Stat. Methodol.) framework. We implement a simplified Laplace approximation that efficiently profiles the posterior density in each parameter direction while correcting for asymmetry, allowing for parametric skew-normal estimation of the marginals. Furthermore, we apply a variational Bayes correction to shift the marginal locations, thereby better capturing the posterior mass. Essential quantities, including factor scores and model-fit indices, are obtained via an adjusted Gaussian copula sampling scheme. For normal-theory SEM, this approach offers a highly accurate alternative to sampling-based inference, achieving near-'maximum likelihood' speeds while retaining the precision of full Bayesian inference.
March 27, 2026 at 5:25 PM
Reposted by Ed Merkle
venpopov.bsky.social
If you are teaching any kind of statistics, probability or modeling classes, you'll love this website. Contains dozens of interactive simulations of random processes, with sliders, different visualizat options, and full numeric log ouput: www.randomservices.org/random/apps/...
February 16, 2026 at 7:43 PM
edgarmerkle.bsky.social
Researchers often treat ordinal variables as continuous. What if we could mimic this in an ordinal factor analysis/IRT model? We propose new identification constraints so that the latent variable goes from 1 to (# of ordered categories), with connections to treating ordinal variables as continuous.
Identification and Scaling of Latent Variables in Ordinal Factor Analysis | Psychometrika | Cambridge Core
Identification and Scaling of Latent Variables in Ordinal Factor Analysis
doi.org
January 21, 2026 at 2:59 PM
Reposted by Ed Merkle
edgarmerkle.bsky.social
Consider submitting a proposal to the (open access) Psychometrika special issue on Variable Selection for Complex Psychometric Data, with a proposal deadline of Jan 15. Full details:
Call for Papers: Psychometrika Special Issue - Psychometric Society
Variable Selection for Complex Psychometric Data
www.psychometricsociety.org
December 9, 2025 at 5:59 PM
edgarmerkle.bsky.social
Consider submitting a proposal to the (open access) Psychometrika special issue on Variable Selection for Complex Psychometric Data, with a proposal deadline of Jan 15. Full details:
Call for Papers: Psychometrika Special Issue - Psychometric Society
Variable Selection for Complex Psychometric Data
www.psychometricsociety.org
December 9, 2025 at 5:59 PM
Reposted by Ed Merkle
handle.invalid
A new semester is upon us! This time, I’m teaching Structural Equation Modeling. Want to follow along? Here you go: jonathantemplin.github.io/Structural-E... and www.youtube.com/playlist?lis... #StatModeling #SEM
Structural Equation Modeling (Fall 2025; University of Iowa: PSQF 6249) – Structural Equation Modeling Fall 2025 (PSQF 6249)
jonathantemplin.github.io
August 28, 2025 at 4:29 PM
Reposted by Ed Merkle
pmetricsoc.bsky.social
Don’t miss out on short courses at IMPS 2025! We have 4 short courses to choose from.
www.psychometricsociety.org/imps2025-sho...
#IMPS2025 #Psychometrics #QuantitativePsychology #rstats
Short Courses for IMPS 2025 - Psychometric Society
www.psychometricsociety.org
May 14, 2025 at 3:01 PM
Reposted by Ed Merkle
brandmaier.bsky.social
You want to fit structural equation models in Julia? No problem with the StructuralEquationModels.jl package. Ships with worked examples and tutorials on how to modify the objective function easily (e.g., adding a regularization penalty). Find our preprint here osf.io/preprints/ps...
May 7, 2025 at 1:37 PM
Reposted by Ed Merkle
vincentab.bsky.social
📚😅🎉

Yay!! I just submitted the complete manuscript of my upcoming book to the publisher!

Learn to easily and clearly interpret (almost) any stats model w/ R or Python. Simple ideas, consistent workflow, powerful tools, detailed case studies.

Read it for free @ marginaleffects.com

#RStats #PyData
Model to Meaning: How to interpret statistical models with marginaleffects for R and Python
April 10, 2025 at 7:06 PM
edgarmerkle.bsky.social
Looks like an interesting paper:
Almost Bayesian: The Fractal Dynamics of Stochastic Gradient Descent
We show that the behavior of stochastic gradient descent is related to Bayesian statistics by showing that SGD is effectively diffusion on a fractal landscape, where the fractal dimension can be accou...
doi.org
April 3, 2025 at 3:37 PM
Reposted by Ed Merkle
avehtari.bsky.social
CmdStanR v 0.9.0 released! According to Andrew Johnson, this should make Windows installation easier plus many other improvements and bug fixes discourse.mc-stan.org/t/cmdstanr-v...

#Bayesian #MCMC
CmdStanR: v0.9.0 Release
Hello all, I’m excited to announce that we have now released CmdStanR v0.9.0! This is a minor release, wrapping up several months of bugfixes, quality-of-life improvements, and updates to documentatio...
discourse.mc-stan.org
March 31, 2025 at 10:00 AM
Reposted by Ed Merkle
coatless.bsky.social
Huzzah! Great news for psychometric software!

Psychometrika now accepts software submissions under "Applications and Case Studies" AND software reviews in their expanded Review Section. This dual recognition elevates the status of programming in the field.

#psychometrics #OpenScience
pmetricsoc.bsky.social Psychometric Society @pmetricsoc.bsky.social · Mar 12
New updates to Psychometrika!

- Theory & Methods now also accepts focus articles with discussion/rejoinder

- Book Review is now Review Section, and includes more topics (lit, book, software, media)

- ARCS is now “Applications and Case Studies,” and includes software as a category
March 12, 2025 at 9:07 PM
edgarmerkle.bsky.social
Here is a new post providing some intuition about the proportional odds restriction in ordinal regression models. Maybe you, or your LLM, will find it useful.
The proportional odds restriction – Ed Merkle
Ordinal regression models often employ a proportional odds restriction, which roughly means that the effect of moving from one ordinal category to the next is constant. Here, we provide an example of ...
ecmerkle.github.io
February 21, 2025 at 3:15 PM
Reposted by Ed Merkle
spinkney.bsky.social
Fellow probabilistic programmers I came up with a parameterization for a Cholesky factor of correlation matrices that looks good. I'm asking to test and see if it works well for you discourse.mc-stan.org/t/updated-ch...

#rstats #statistics #bayesian
Updated cholesky corr parameterization testing
Hi everyone, I’m asking if people could test out this parameterization of the Cholesky factor of correlation matrices? From my tests on a macpro m1, it looks to be much faster and I can easily sample...
discourse.mc-stan.org
February 20, 2025 at 1:50 PM
Reposted by Ed Merkle
vincentab.bsky.social
{tinyplot} 0.3.0 is out! 🚨

It's a lightweight #Rstats 📦 to draw beautiful and complex plots, using an ultra-simple and concise syntax.

This is a massive release! @gmcd.bsky.social @zeileis.org and I worked hard to add tons of new themes and plot types.

Check it out!

grantmcdermott.com/tinyplot/
February 5, 2025 at 9:48 PM
Reposted by Ed Merkle
avehtari.bsky.social
If you know simulation based calibration checking (SBC), you will enjoy our new paper "Posterior SBC: Simulation-Based Calibration Checking Conditional on Data" with Teemu Säilynoja, @marvinschmitt.com and @paulbuerkner.com
arxiv.org/abs/2502.03279 1/7
Title: Posterior SBC: Simulation-Based Calibration Checking Conditional on Data Authors: Teemu Säilynoja, Marvin Schmitt, Paul Bürkner, Aki Vehtari Abstract: Simulation-based calibration checking (SBC) refers to the validation of an inference algorithm and model implementation through repeated inference on data simulated from a generative model. In the original and commonly used approach, the generative model uses parameters drawn from the prior, and thus the approach is testing whether the inference works for simulated data generated with parameter values plausible under that prior. This approach is natural and desirable when we want to test whether the inference works for a wide range of datasets we might observe. However, after observing data, we are interested in answering whether the inference works conditional on that particular data. In this paper, we propose posterior SBC and demonstrate how it can be used to validate the inference conditionally on observed data. We illustrate the utility of posterior SBC in three case studies: (1) A simple multilevel model; (2) a model that is governed by differential equations; and (3) a joint integrative neuroscience model which is approximated via amortized Bayesian inference with neural networks.
February 6, 2025 at 10:11 AM
Reposted by Ed Merkle
pmetricsoc.bsky.social
The Psychometric Society invites IMPS 2024 presenters to submit manuscripts to the 2024 Proceedings.

Intent to Submit Deadline: February 14, 2025
Manuscript Deadline: March 21, 2025

www.psychometricsociety.org/imps2024-pro...

#psychometricsociety #psychometrics #quantitativepsychology
January 30, 2025 at 2:56 PM
Reposted by Ed Merkle
adrianhill.de
You think Jacobian and Hessian matrices are prohibitively expensive to compute on your problem? Our latest preprint with @gdalle.bsky.social might change your mind!
arxiv.org/abs/2501.17737
🧵1/8
Figure comparing automatic differentiation (AD) and automatic sparse differentiation (ASD). (a) Given a function f, AD backends return a function computing vector-Jacobian products (VJPs). (b) Standard AD computes Jacobians row-by-row by evaluating VJPs with all standard basis vectors. (c) ASD reduces the number of VJP evaluations by first detecting a sparsity pattern of non-zero values, coloring orthogonal rows in the pattern and simultaneously evaluating VJPs of orthogonal rows. The concepts shown in this figure directly translate to forward-mode, which computes Jacobians column-by-column instead of row-by-row.
January 30, 2025 at 2:32 PM
Reposted by Ed Merkle
clintin.bsky.social
Now out in PNAS, we provide a conceptual framework for assessing replication decisions and replication reform.

Do you view the scientific literature as a "book of truths" or a "book of conversations"?

www.pnas.org/doi/abs/10.1...

#philsci #science #SciSci #Metascience
PNAS
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...
www.pnas.org
January 28, 2025 at 2:44 PM
Reposted by Ed Merkle
pmetricsoc.bsky.social
Call for Abstracts for IMPS 2025

The Psychometric Society Invites You to Submit an Abstract for IMPS 2025!

The abstract submission portal is scheduled to open Jan 29, 2025

Please see the society website for details: www.psychometricsociety.org/post/imps-20...
IMPS 2025 Abstract Submission - Psychometric Society
Submission Deadline: February 28, 2025
www.psychometricsociety.org
January 22, 2025 at 2:31 PM
Reposted by Ed Merkle
zeileis.org
Our friend and colleague Fritz Leisch died in April last year. In a new contribution to The R Journal we honor Fritz and commemorate his many contributions to science in general and to the R community in particular. #rstats

journal.r-project.org/articles/RJ-...
Remembering Friedrich
This article remembers our friend and colleague Fritz Leisch (1968--2024) who sadly died earlier this year. Many of the readers of The R Journal will know Fritz as a member of the R Core Team and for ...
journal.R-project.org
January 22, 2025 at 3:52 PM