Kristoffer Magnusson
@rpsychologist.com
📤 1317
📥 1405
📝 132
Mostly stats, visualization, open science, and psychotherapy.
https://rpsychologist.com
pinned post!
Introducing PowerLMM.js! A new tool for power analysis of longitudinal linear mixed-effects models (LMMs) – with support for missing data, plus non-inferiority and equivalence tests.
powerlmmjs.rpsychologist.com
Would really appreciate your feedback as I refine this app! Details below 🧵👇
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11 months ago
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Kristoffer Magnusson
Just added to PowerLMM.js v0.3: Interactive power contour plots! Visualize how statistical power changes across parameter combinations.
powerlmmjs.rpsychologist.com?view=contour
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10 days ago
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Just added to PowerLMM.js v0.3: Interactive power contour plots! Visualize how statistical power changes across parameter combinations.
powerlmmjs.rpsychologist.com?view=contour
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10 days ago
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Wasn't that happy with how performance crashed as time points grew, so I dusted off some linear algebra to optimize the calculations. Benchmark showed a ~1Mx speedup using new implementation (with 100 time points) 😅
add a skeleton here at some point
18 days ago
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Kristoffer Magnusson
Matti Vuorre
20 days ago
🎉
@rpsychologist.com
's PowerLMM.js is the online statistics application of the year 2025 🎉
powerlmmjs.rpsychologist.com
- Calculate power (etc) for multilevel models - Examine effects of dropout and other important parameters - Fast! (Instant results)
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Dan Quintana
20 days ago
Who’s gonna pay
@rpsychologist.com
to make a mega tool converting all g*power analysis types to an interpretable web tool like this?
add a skeleton here at some point
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New release of PowerLMM.js! Browser-based power analysis for longitudinal models with dropout. Now includes: - Power analysis summary report - Reproducible & shareable configs (URL/JSON) - Calculations validated against R - Hypothesis region visualization
powerlmmjs.rpsychologist.com
20 days ago
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Turns out proportions aren't collapsible after all. Take that, OR haters. "Globally, approximately 3.3% of the population reports using AAS, with prevalence rates of 6.4% among men [2] and 4% among women [3]."
5 months ago
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I watched this so you don’t have to. A couple of highlights: ”I sometimes say that 'screen use', when putting that into statistical models, it’s sort of like looking at 'car use' when trying to find out why injuries are happening from car accidents” 🇳🇴
www.youtube.com/live/XKo6oUY...
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Digital media and its impact on children and adolescents – livestreamed Nordic and EU expert meeting
YouTube video by Folkhälsomyndigheten
https://www.youtube.com/live/XKo6oUYnUqU?si=-GqspS2iqMth5EFf&t=3202
6 months ago
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Great talk by
@jeremylabrecque.bsky.social
"Before and after causal inference: recognizing causal questions and answering them when assumptions are violated"
www.youtube.com/watch?v=9B-X...
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2025 CAUSALab Methods Series with Jeremy Labrecque
YouTube video by CAUSALab at Harvard T.H. Chan
https://www.youtube.com/watch?v=9B-XyxW7R6w&list=PLlPWrOkuvI8S6t00nMDYnwhGvvkYUwhJe
6 months ago
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Not sure where to start with this one. Internet gaming addiction… is a risk factor for internet gaming disorder
6 months ago
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Regarding the expert consensus on smartphone use: let’s not forget that the related “behavioral addiction” gaming disorder, is essentially a copy-paste job. Below is a visual comparison of the ICD-11 criteria for gaming and gambling disorder—essentially a substitution of terms.
6 months ago
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Kristoffer Magnusson
Adam Kucharski
6 months ago
A common sentiment is “I can’t share my code because it’s messy and there might be errors” But if it’s that untrustworthy, why are you publishing the results it generates?
add a skeleton here at some point
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I see this a lot in longitudinal analysis—people assume missingness can depend on random effects (like slopes). But those aren’t conditioned on, so that kind of missingness would be non-ignorable (MNAR).
add a skeleton here at some point
7 months ago
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Kristoffer Magnusson
Alex Coppock
7 months ago
This new package for mediation is great! The user interface is *so intuitive* but the unsung hero of this software is the documentation:
add a skeleton here at some point
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Kristoffer Magnusson
Tim Kaiser
7 months ago
Despite the well-polished workflow of this package, I tried to analyze the “useless data set” that comes with it using {mediation}. Treatment and mediator were (strongly) confounded, so we need to pay close attention to the sensitivity analysis!
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Darren Dahly
7 months ago
To think that some scientists working in medicine will even brag about not understanding the methods used in the papers they "lead". Like it's beneath them. What a world.
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Matti Vuorre
7 months ago
This is great. It even handles binary and count outcomes appropriately!
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🚨New R package! {easymediation}🚨 The *Simplest* and *Most Correct* Way to Do Causal Mediation Analysis Are you tired of explaining mediation analysis to your colleagues? Just send them this package.
github.com/rpsychologis...
7 months ago
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Step 1: Say data are MNAR Step 2: Toss in random values Step 3: Call it conservative I’ll definitely adopt this model-free way of handling MNAR, what could go wrong?
7 months ago
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Amazing observation in a paper: people use smartphones while waiting. I’ve also observed that people read magazines they’d never touch anywhere else while waiting. Proposing a new disorder: "Compulsive Magazine Reading". Urgent need for intervention programs
7 months ago
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Been reading up on causal prediction – let me know if I’ve got this right: Clinical prediction: Hard. Causal inference: Hard. Causal prediction: Combines the hardest parts of both. Predict outcomes we can’t observe, and evaluate models by making even more assumptions about an unobservable target.
7 months ago
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Kristoffer Magnusson
Gary Collins
7 months ago
NEW PAPER: Updated CONSORT-2025 for reporting randomised trials is now available in the
@bmj.com
@jama.com
,
@thelancet.bsky.social
,
@plos.org
and
@naturemedicine.bsky.social
—>
www.bmj.com/content/389/...
#openscience
#transparency
#medsky
#statssky
#episky
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Hear me out, psychologists are the OG vibe coders. Picking factors by squinting at scree plots, naming latent variables on instinct, fitting SEMs based on celestial drawings, and publishing without a care.
add a skeleton here at some point
7 months ago
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Kristoffer Magnusson
Julia M. Rohrer
9 months ago
New blog post! Sometimes, when reviewing a manuscript, it's really unclear to me what precisely the authors are trying to do -- which makes it hard to evaluate the work properly. So, here's some advice for how to ensure that readers don't get lost.
www.the100.ci/2025/02/17/r...
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Reviewer notes: Avoid any ambiguity about analysis aims
For any central statistical analysis that you report in your manuscript, it should be absolutely clear for readers why the analysis is being conducted in the first place – that is, the analysis goal s...
https://www.the100.ci/2025/02/17/reviewer-notes-avoid-any-ambiguity-about-analysis-aims/
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Kristoffer Magnusson
Prof Andy Field
10 months ago
Trying to compile a list of people with active pedagogic interests in teaching statistics
go.bsky.app/Qg6YSq6
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Darren Dahly
10 months ago
Please stop telling me about risk factors. 🙏😖 (ICYMI)
statsepi.substack.com/p/sorry-what...
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Kristoffer Magnusson
Added a variogram to the app! I'm experimenting with showing the non-stationarity of correlations in a random slopes model.
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11 months ago
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Kristoffer Magnusson
Julia M. Rohrer
11 months ago
This looks *extremely* neat. Kristoffer consistently provides exceptionally useful tools and visualizations 🤩
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Matti Vuorre
11 months ago
💙 this web app for examining multilevel models' precision & sample size planning. (Now I just need to pair it with Claude to input the numeric predictions from my verbal descriptions 😉.)
add a skeleton here at some point
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Introducing PowerLMM.js! A new tool for power analysis of longitudinal linear mixed-effects models (LMMs) – with support for missing data, plus non-inferiority and equivalence tests.
powerlmmjs.rpsychologist.com
Would really appreciate your feedback as I refine this app! Details below 🧵👇
loading . . .
11 months ago
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Mental Health Disorder Trends in Denmark According to Age, Calendar Period, and Birth Cohort "This cohort study found that more recent birth cohorts and calendar periods had higher sex-specific incidence rates of any mental disorder"
jamanetwork.com/journals/jam...
12 months ago
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Kristoffer Magnusson
Altmetric
12 months ago
We’re no experts but this sounds like it might be suboptimal for disseminating research.
add a skeleton here at some point
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The plot thickens
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12 months ago
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Kristoffer Magnusson
Maarten van Smeden
12 months ago
Best social media innovation of 2024: a platform that is exactly like another was 5 years ago
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Kristoffer Magnusson
Veli-Matti Karhulahti
12 months ago
Whenever I accidentally see my GS recommendations it gives a harsh reminder of the state of art. Despite the field lacking understanding of GD let alone its measurement, multiple studies driven by these measures come out *every day*. At least publishing business is doing good
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This is the only starter pack I want to be added to
add a skeleton here at some point
12 months ago
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Important question: Why is it called a *Bayesian* Bicep Curl? 🤔 And what's a Frequentist Curl?
12 months ago
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Kristoffer Magnusson
Julia M. Rohrer
12 months ago
When a study talks about various things that could bias estimates but never explicitly addresses the analysis goal in the first place
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Me and
@larsklintwall.bsky.social
have been working on an app that will allow participants to interactively build networks of perceived causal relations. I’ve put together a demo website, that I’m soft-launching while we continue to pilot the app
pecan-tool.rpsychologist.com
🧵👇
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Interactive Perceived Causal Problem Networks (PECAN) Demo
Interactive Perceived Causal Problem Networks (PECAN) Demo
https://pecan-tool.rpsychologist.com
12 months ago
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Kristoffer Magnusson
Björn Siepe
12 months ago
Simulation studies are essential for methods research. How well are they conducted & reported? How can we improve their quality? Out now in Psychological Methods, see 🧵 below. With
@fbartos.bsky.social
,
@timpmorris.bsky.social
,
@boulesteixlaure.bsky.social
,
@danielheck.bsky.social
& Samuel Pawel
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Working on some network stuff. It's oddly satisfying going from this network spaghetti to something a bit more organized
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12 months ago
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Kristoffer Magnusson
Paul Hünermund
12 months ago
When I started to supervise master theses, students had somehow heard of the PROCESS macro. Even some colleagues were working with it. When I looked into it, I couldn't believe what I saw. Then
@dingdingpeng.the100.ci
approached me to write a paper about its shortcomings. Now it reached 200 cites! 📈
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This is way too accurate 😂
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12 months ago
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Oh are we doing "random confounding" again
add a skeleton here at some point
about 1 year ago
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Quote a favorite film. Gif only
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about 1 year ago
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ok I will build it
add a skeleton here at some point
about 1 year ago
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This is getting out of hand, we need a starter pack of starter packs
about 1 year ago
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So are we doing Bayes vs NHST next?
about 1 year ago
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Kristoffer Magnusson
Joar Øveraas Halvorsen
about 1 year ago
Not very surprising. One of the most prominent and widely accepted conclusions in clinical psychology - the Dodo bird verdict - is essentially built on this (mis)interpretation. 👇
add a skeleton here at some point
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I don't think the ”problem” is tidyverse vs base R. The
#rstats
community's culture is shaped by non-programmers, and that's a _huge_ strength, fostering a DIY community where lots of people feel comfortable trying things out, creating resources, and getting stuff done.
add a skeleton here at some point
about 1 year ago
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