Magnus Johansson
LightNews LightNews
banner
pgmj.bsky.social
Magnus Johansson
@pgmj.bsky.social
2.4K followers 1.3K following 350 posts

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

Videos
Psychology 41%
Sociology 12%
Posts Replies Media Videos
Pinned
pgmj.bsky.social
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

Reposted by Magnus Johansson

mattansb.msbstats.info
Mattan S. Ben-Shachar @mattansb.msbstats.info · 1d
Here it is! #rstats

Reposted by Shannon Vallor, Dorothy Bishop, Peter Thorne , and 23 more

mysteriosox.bsky.social
Count Mysterioso @mysteriosox.bsky.social · 3d
This is quite a post

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

Reposted by Magnus Johansson

solomonkurz.bsky.social
Solomon Kurz @solomonkurz.bsky.social · 6d
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

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · 6d
Yes, I could have procrastinated until tomorrow to optimize... Looking forward to see you there!

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · 6d
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

ibddoctor.bsky.social
IBD Doctor @ibddoctor.bsky.social · 7d
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The U.S. Food and Drug Administration today published draft guidance designed to facilitate the use of Bayesian methodologies in clinical trials of drugs and biologics, helping drug developers make be...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

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · 7d
Undrar hur de mäter det.

Reposted by Magnus Johansson

infotainment.bsky.social
Jay Patel @infotainment.bsky.social · 8d
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

tonybiglan.bsky.social
Tony Biglan President, Values to Action @tonybiglan.bsky.social · 8d
@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

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · 12d
I like them, but in this format (from smped.github.io/SimpleUpset/... )

Reposted by Martin Lang, Magnus Johansson, Patrick S. Forscher , and 3 more

eikofried.bsky.social
Eiko Fried @eikofried.bsky.social · 13d
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...
WARN-D machine learning competition is live » Eiko Fried
If you share one single thing of our team in 2026—on social media or per email with your colleagues—please let it be this machine learning competition. It was half a decade of work to get here, especi...
eiko-fried.com

Reposted by Magnus Johansson, Paul Goldsmith-Pinkham

vincentab.bsky.social
Vincent Arel-Bundock @vincentab.bsky.social · 14d
My poster got allocated prime real estate at the conference: High traffic, captive audience.

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · 18d
You are welcome! Glad to contribute something back. I've enjoyed reading many of your posts :)

Reposted by Magnus Johansson

solomonkurz.bsky.social
Solomon Kurz @solomonkurz.bsky.social · 18d
The 1.3.0 version of my {brms} + {tidyverse} translation of Kruschke's "Doing Bayesian data analysis" is up!

solomon.quarto.pub/dbda2

#rstats

1/8
Doing Bayesian Data Analysis in brms and the tidyverse
solomon.quarto.pub

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · 18d
That is also recommended in this paper:

Balzer, L. B., & Westling, T. (2023). Invited Commentary: Demystifying Statistical Inference When Using Machine Learning in Causal Research. American Journal of Epidemiology, 192(9), 1545–1549. doi.org/10.1093/aje/...
Invited Commentary: Demystifying Statistical Inference When Using Machine Learning in Causal Research
Abstract. In this issue, Naimi et al. (Am J Epidemiol. 2023;192(9):1536–1544) discuss a critical topic in public health and beyond: obtaining valid statist
doi.org

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · 23d
Having to intermittently save backup copies (since MS OneDrive can't be trusted either) seems like something one should not have to do these days.

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · 23d
I'm writing a report with a deadline two days from now and Word keeps crashing 2-3 times a day. While the document is lengthy and has a lot of figures, it is just astounding that Microsoft haven't been able to make this program more stable after 40+ years of development.

Reposted by Linda J. Skitka, Olivier Corneille, Alexander Wuttke , and 4 more

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · 23d
"40 percent of MRI signals do not correspond to actual brain activity"; "Since tens of thousands of fMRI studies worldwide are based on this assumption, our results could lead to opposite interpretations in many of them.”
www.tum.de/en/news-and-...
40 percent of MRI signals misinterpreted
Interpretation of numerous MRI data may be incorrect: blood flow is not a reliable indicator of brain activity.
www.tum.de

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · 23d
Maybe, maybe not. bsky.app/profile/drda...
drdanvers.bsky.social Alex Danvers @drdanvers.bsky.social · 24d
Yikes!
“Increased oxygen consumption – for instance in areas involved in calculation – did not coincide with the expected rise in blood flow. …analyses showed that these regions met their additional energy demand by extracting more oxygen from the unchanged blood supply.”

www.tum.de/en/news-and-...
40 percent of MRI signals misinterpreted
Interpretation of numerous MRI data may be incorrect: blood flow is not a reliable indicator of brain activity.
www.tum.de

Reposted by Magnus Johansson, Jill A. Jacobson

drdanvers.bsky.social
Alex Danvers @drdanvers.bsky.social · 24d
Yikes!
“Increased oxygen consumption – for instance in areas involved in calculation – did not coincide with the expected rise in blood flow. …analyses showed that these regions met their additional energy demand by extracting more oxygen from the unchanged blood supply.”

www.tum.de/en/news-and-...
40 percent of MRI signals misinterpreted
Interpretation of numerous MRI data may be incorrect: blood flow is not a reliable indicator of brain activity.
www.tum.de

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · 29d
I'd ask the same question about any VAS rating scale.

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · Dec 14
Sounds like a proper winter. Here it only rains and +2-7 C temp. Dark and dreary :(

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · Dec 13
Linking to the actual research paper in the article would be helpful.

Reposted by Magnus Johansson

solomonkurz.bsky.social
Solomon Kurz @solomonkurz.bsky.social · Dec 12
Another day, and another reference to these bangers. Contemporary causal inference has fundamentally changed the way I think about control variables and mediation analyses. These can show you why:

doi.org/10.1177/2515...
doi.org/10.1111/spc3...
doi.org/10.1177/2515...
Sage Journals: Discover world-class research
Subscription and open access journals from Sage, the world's leading independent academic publisher.
doi.org

Reposted by Dorothy Bishop, David Chester, Andrew K Przybylski , and 5 more

ianhussey.mmmdata.io
Ian Hussey @ianhussey.mmmdata.io · Dec 12
Keeping this at hand in case I need to point to it and tap

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · Dec 12
Just realized I have an old gdrive folder with similar content, if it could be of interest: drive.google.com/drive/mobile...
Funktionell kontextualism - Google Drive
drive.google.com

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · Dec 12
Nice. This is also a great read: www.scribd.com/doc/29106580...
Gifford and Hayes - Functional Contextualism 1999 | PDF
Gifford and Hayes - Functional Contextualism 1999
www.scribd.com

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · Dec 11
Might this be applicable? journals.sagepub.com/doi/10.1177/...
These Are Not the Effects You Are Looking for: Causality and the Within-/Between-Persons Distinction in Longitudinal Data Analysis - Julia M. Rohrer, Kou Murayama, 2023
In psychological science, researchers often pay particular attention to the distinction between within- and between-persons relationships in longitudinal data a...
journals.sagepub.com

Reposted by Alexander Wuttke, Magnus Johansson

ianhussey.mmmdata.io
Ian Hussey @ianhussey.mmmdata.io · Dec 8
Today’s example of “self reported behaviour is a poor proxy of behaviour”: environmental behaviour
cameronbrick.bsky.social Cameron Brick @cameronbrick.bsky.social · Dec 8
Also, "research involving self-reports often leads to fundamentally different results than research focusing on actual behavior in incentivized settings"

2/3

pgmj.bsky.social
Magnus Johansson @pgmj.bsky.social · Dec 8
Thanks, lots of interesting things discussed! Curious about why a zero-inflated or hurdle negbin was not used? ”We employ negative binomial regression models, which are well-suited to the outcome variable’s distribution — right-skewed with a large concentration of zero values.”