Magnus Johansson

@pgmj.bsky.social

2.4K followers 1.4K following 360 posts

PhD & lic. psychologist. Research specialist at Karolinska Institutet @ki.se . R package for Rasch psychometrics: pgmj.github.io/easyRasch/
#openscience, #prevention, #psychometrics, #rstats, #photo

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Sociology 12%

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Magnus Johansson @pgmj.bsky.social · Mar 11

My simulation study on item misfit detection in Rasch models is published. We should leave rule-of-thumb critical values for GOF metrics behind us and use simulation/bootstrap methods to determine cutoffs appropriate for the data and items being analyzed. pgmj.github.io/rasch_itemfit/ #psychometrics

Detecting item misfit in Rasch models

pgmj.github.io

Magnus Johansson @pgmj.bsky.social · 2d

Yeah the 40 could be my one and only lens. I used to have the 20, 40 and 90, a super compact and performing trio.

Magnus Johansson @pgmj.bsky.social · 2d

Those Voigtländer SL lenses for Nikon are all really nice.

Magnus Johansson @pgmj.bsky.social · 3d

Is this PF as described within ACT?

Magnus Johansson @pgmj.bsky.social · 3d

I switched from Spotify to Qobuz some time ago, mostly for ethical reasons (pays artists better, etc). But the improvement in sound quality is really obvious when using a decent listening rig. And the curated playlists and magazine articles are really nice, especially on an iPad or similar.

Lennart Jonasson @lennson.bsky.social · 4d

Magnus Johansson @pgmj.bsky.social · 5d

Unexpected to see the Cochrane Risk of Bias tool v2 (2019) more or less asking for tests of baseline differences in RCTs when this is generally considered bad practice, for instance by the CONSORT guidelines.

Reposted by Dorothy Bishop, Magnus Johansson, Ingo Rohlfing , and 1 more Dorothy Bishop, Magnus Johansson, Ingo Rohlfing, Matti Vuorre

Michèle Nuijten @michelenuijten.bsky.social · 6d

I wrote a blog for the Meta-Research Center expressing my infinite frustration about not getting data. What else is new, you might think? Well, I added an extra layer of annoyance directed at the journals who do NOTHING to enforce promised data sharing.

metaresearch.nl/blog/2026/2/...

Promised Data Unavailable? – I’m Sorry, Ma’am, There’s Nothing We Can Do — Meta-Research Center

This blogpost has been written by Michèle Nuijten. Michèle is an assistant professor of our research group who investigates reproducibility and replicability in psychology. Also, she is the developer ...

metaresearch.nl

Magnus Johansson @pgmj.bsky.social · 8d

Ja bra. Men blev det 18 av 81? www.mitti.se/nyheter/natl...

Magnus Johansson @pgmj.bsky.social · 9d

The file drawer could be vast.

Magnus Johansson @pgmj.bsky.social · 9d

Yes, and other aspects. Generally wary of research on your own product. Independent research replicating findings would be crucial.

Magnus Johansson @pgmj.bsky.social · 9d

I see many takes on the new Anthropic LLM-assisted programming study but no discussion about potential bias due to their financial interests in their own product?

Magnus Johansson @pgmj.bsky.social · 10d

I have made an R package for test equating using the Leunbach method. Thanks to the gracious sharing of DIGRAM source code by Svend Kreiner and some assistance of Claude Opus 4.5, the package `leunbachR` is now available on GitHub: pgmj.github.io/leunbachR/in...
#rstats #psychometrics

Leunbach Test Equating

Implements the Leunbach test equating method, following the DIGRAM software written by Svend Kreiner. Both direct and indirect equating is available. See Adroher et al. 2019 (DOI 10.1186/s12874-019-07...

pgmj.github.io

Reposted by Magnus Johansson

Solomon Kurz @solomonkurz.bsky.social · 12d

All my #rstats ebooks are now in the quarto format, and hosted on Quarto Pub. Their old bookdown links will all be dead by the weekend.

1/3

Reposted by Magnus Johansson, Mathieu Hainselin, Matti Vuorre

Neuroskeptic @neuroskeptic.bsky.social · 12d

I hate this: "The Editors have retracted this article... the Mini-Mental State Examination (MMSE) instrument was used without proper permissions" link.springer.com/article/10.1... The MMSE is a series of 11 simple questions. A perfectly good paper is retracted because you can copyright 11 questions

Retraction Note: Cognitive function assessed by Mini-mental state examination and risk of all-cause mortality: a community-based prospective cohort study - BMC Geriatrics

BMC Geriatrics -

link.springer.com

Reposted by Brian A. Nosek, David Lazer, Brendan Nyhan , and 7 more Brian A. Nosek, David Lazer, Brendan Nyhan, Seema Jayachandran, Alexander Wuttke, Magnus Johansson, Ian Hussey, Paolo Crosetto, Samuel Bentolila, Winston T. Lin

Jamie Cummins @jamiecummins.bsky.social · 18d

Comparing registrations to published papers is essential to research integrity - and almost no one does it routinely because it's slow, messy, and time-demanding.

RegCheck was built to help make this process easier.

Today, we launch RegCheck V2.

🧵

regcheck.app

RegCheck

RegCheck is an AI tool to compare preregistrations with papers instantly.

regcheck.app

Reposted by Magnus Johansson

Annual Reviews @annualreviews.bsky.social · 19d

📢 The most recent volume of the Annual Review of Psychology is now online! The most read article so far is "How Do Psychologists Determine Whether a Measurement Scale Is Good? A Quarter-Century of Scale Validation with Hu & Bentler (1999)" by @dmcneish.bsky.social.
arevie.ws/4jRYY6B

Reposted by Magnus Johansson

Mattan S. Ben-Shachar @mattansb.msbstats.info · 21d

Here it is! #rstats

Reposted by Shannon Vallor, Dorothy Bishop, Peter Thorne , and 23 more Shannon Vallor, Dorothy Bishop, Peter Thorne, Mor Naaman, Gavin A. Schmidt, Elena Litchman, Tom Clark, Steve Peers, Lesley A. Hall, Peter Holmes, Magnus Johansson, Daniel W. Drezner, Micaël Castanheira, Alan Richardson, Vincent Noël, Andrew L. Whitehead, Jacob T. Levy, Christine Kooi, Stephen Ryan, Mark Robinson, David Murakami Wood, Mark Rice, Thomas Masterson, Pauline Stafford, Simon Lester, Farah Mendlesohn

Count Mysterioso @mysteriosox.bsky.social · 23d

This is quite a post

www.planetearthandbeyond.co/p/reality-is...

Reposted by Magnus Johansson

Paula Smith @paulasmith.co.uk · 25d

My favourite from 2025 using @ilfordphoto.com film. This (I think) is going to be the cover of my next zine...

Ilford Ortho+ 80 developed with Ilfotec HC 1+31. Taken with a Bronica SQAi & 80mm.

#fridayfavourites #2025fave #filmphotography

A black and white image of a large oak tree trunk with 'Wake Up' graffitied on it. In the background there are more oak trees receding into the distance.

Reposted by Magnus Johansson

Solomon Kurz @solomonkurz.bsky.social · 26d

The 0.5.0 version of my {brms} + {tidyverse} translation of McElreath's "Statistical Rethinking" (2nd ed) is up!

solomon.quarto.pub/sr2/

1/3

#rstats

Statistical rethinking 2 with rstan and the tidyverse

solomon.quarto.pub

Magnus Johansson @pgmj.bsky.social · 26d

Yes, I could have procrastinated until tomorrow to optimize... Looking forward to see you there!

Magnus Johansson @pgmj.bsky.social · 26d

With more than 24h to the deadline, I have submitted an abstract to the Scandinavian Applied Measurement Conference. Join us to talk about #psychometrics and #measurement in Copenhagen, June 8-10th, 2026. biostat.ku.dk/SAMC/

SAMC

biostat.ku.dk

Reposted by Magnus Johansson

IBD Doctor @ibddoctor.bsky.social · 27d

This is a big deal for speeding up clinical trials, and for pediatric use after adult trials have proved successful. The @USFDA goes Bayesian.
A win for #IBD patients, and especially for kids with #IBD. @crohnsandcolitisau.bsky.social @f2harrell.bsky.social
www.fda.gov/news-events/...

FDA Issues Guidance on Modernizing Statistical Methods for Clinical Trials

The U.S. Food and Drug Administration today published draft guidance designed to facilitate the use of Bayesian methodologies in clinical trials of drugs and biologics, helping drug developers make be...

www.fda.gov

Magnus Johansson @pgmj.bsky.social · 27d

Undrar hur de mäter det.

Reposted by Magnus Johansson

Jay Patel @infotainment.bsky.social · 28d

This is the avant-garde preprint service (hosted on AT Protocol) that I've been dreaming of.

If it's a small fraction of its vision down the road, I'd still be happy.

Check out Chive (docs.chive.pub/getting-star...).

- scholar owned
- open/community peer review
- semantic linking to terms

Reposted by Magnus Johansson

Tony Biglan President, Values to Action @tonybiglan.bsky.social · 28d

@bsky.app www.nytimes.com/2026/01/12/c...
another naked example of profits over people!

E.P.A. to Stop Considering Lives Saved When Setting Rules on Air Pollution

www.nytimes.com

Magnus Johansson @pgmj.bsky.social · Jan 8

I like them, but in this format (from smped.github.io/SimpleUpset/... )

Reposted by Martin Lang, Magnus Johansson, Patrick S. Forscher , and 3 more Martin Lang, Magnus Johansson, Patrick S. Forscher, Anthony J. Evans, Larry W. Hunter, Jill A. Jacobson

Eiko Fried @eikofried.bsky.social · Jan 7

After 5 years of data collection, our WARN-D machine learning competition to forecast depression onset is now LIVE! We hope many of you will participate—we have incredibly rich data.

If you share a single thing of my lab this year, please make it this competition.

eiko-fried.com/warn-d-machi...