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Rob Cavanaugh

@rbcavanaugh.bsky.social
514 followers 650 following 106 posts

Assistant Professor in quantitative methods @mgbuniversity.bsky.social, speech-language pathologist by training. Enthusiastic about quantitative methods in rehabilitation research and health services research for aphasia. 🥾🏔️🦮🍕

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Reposted by Rob Cavanaugh
Vincent Arel-Bundock @vincentab.bsky.social · 04/09/2026
Big news! 🎉 𝚖𝚊𝚛𝚐𝚒𝚗𝚊𝚕𝚎𝚏𝚏𝚎𝚌𝚝𝚜 1.0.0 for #Rstats is out. It’s a big number and it feels like a big step. I wrote a blog on the challenges of interpreting statistical models, SPEED, cool new features, the future, and a 5 year package development and writing odyssey. arelbundock.com/posts/margin...
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Quantitude the Podcast @quantitude.bsky.social · 01/09/2026
S8E01 The True Crimes of Null Hypothesis Significance Testing Patrick and Greg find it deeply unfair that the podcast hasn’t grown popular enough to fund a Quantitude jet. So they try to make it a true crime podcast, and revisit the case of Null Hypothesis Significance Testing.
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ASHA Journals @ashajournals.bsky.social · 10/07/2026
The American Journal of Speech-Language Pathology is seeking an Editor-in-Chief for Acquired Language & Cognitive Communication. We're accepting applications from people with strong editorial leadership & expertise. Email CV to kgnanasekhar@asha.org by 7/24.
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Kristoffer Magnusson @rpsychologist.com · 25/06/2026
New interactive blog! "Why Adjusted Regression Coefficients Are Less Descriptive Than They Look" rpsychologist.com/descriptive-...
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Daniel 🕹️ @strengejacke.de · 24/06/2026
A new paper by @dominiquemakowski.bsky.social, @mattansb.msbstats.info, me and colleagues just out! We show how to choose informative priors in Bayesian regression models using a systematic simulation study and a practical step-by-step tutorial in #Rstats and #Stan! doi.org/10.3389/fpsy... >
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Madeline Cruice @madelinecruice.bsky.social · 31/05/2026
Pssst: to those interested in #aphasia and #storytelling I am giving my inaugural at @citystgeorges.bsky.social on Wednesday 10 June. Please come! Register here for details: www.citystgeorges.ac.uk/news-and-eve...
citystgeorges.ac.uk
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Magnus Johansson @pgmj.bsky.social · 23/04/2026
I've made an R package for Bayesian Rasch #psychometrics with brms models, easyRaschBayes (on CRAN), implementing simple functions to create figures and tables with model fit metrics, etc. Attaching figures from conditional item infit, item-restscore with GK gamma, and the log-likelihood criterion.
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Julia M. Rohrer @dingdingpeng.the100.ci · 22/04/2026
Good news everyone 🥳 Our (w @vincentab.bsky.social) primer on models as prediction machines (with the marginaleffects package) is finally officially published!> journals.sagepub.com/doi/10.1177/...
journals.sagepub.com
Models as Prediction Machines: How to Convert Confusing Coefficients Into Clear Quantities - Julia M. Rohrer, Vincent Arel-Bundock, 2026
Psychological researchers usually make sense of regression models by interpreting coefficient estimates directly. This works well enough for simple linear model...
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Maya Henry @mayalhenry.bsky.social · 10/04/2026
New preprint exploring how conceptual representations can be decoded in people with aphasia using fMRI. Grateful for an exciting collaboration with @jerrytang.bsky.social, @alexanderhuth.bsky.social, @smwilson.bsky.social!
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Aidan Wright @aidangcw.bsky.social · 25/03/2026
📣 The 2026 SMaRT Workshops schedule is officially LIVE — with workshops covering SEM, MLM, dyadic methods, time series, machine learning, clinical trials design, and more. STATS NERD SUMMER is HERE. Come learn something. 🧑‍🎓 smart-workshops.com/workshops Please share and RP🙏 More info 👇 1/n
smart-workshops.com
Workshops — SMaRT Workshops
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Yannic Meier @ymeier.bsky.social · 04/03/2026
🚨 New Blog Post 🚨 I wrote my very first blog post 😊 This post is for quantitative researchers working with negatively worded Likert-scale items and haven't heard that these items can cause problems. I outline key issues, describe alternatives, and recommend lit. yannicmeier.de/2026/03/03/w...
yannicmeier.de
Why reversed items can be problematic in survey research
In quantitative psychological research, questionnaires with Likert-style items are mostly used to assess variables like emotions, cognitions, and dispositions. Sometimes, it is possible to fall bac…
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Richard McElreath 🐈‍⬛ @rmcelreath.bsky.social · 09/12/2025
I'm teaching Statistical Rethinking again starting Jan 2026. This time with live lectures, divided into Beginner and Experienced sections. Will be a lot more work for me, but I hope much better for students. I will record lectures & all will be found at this link: github.com/rmcelreath/s...
course schedule as a table. Available at the link in the post.
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Jose G Centeno @centenoj.bsky.social · 04/12/2025
Call for papers 👇👇👇🚨 clinicalaphasiologyconference.org/cac-2026/
clinicalaphasiologyconference.org
CAC 2026
The 55th Clinical Aphasiology Conference Tuesday May 26th – Friday May 29th, 2026Sheraton Hotel at Station Square, Pittsburgh, Pennsylvania, USA The annual Clinical Aphasiology Conference (CA…
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Rob Cavanaugh @rbcavanaugh.bsky.social · 01/12/2025
Folks who teach stats to graduate students in applied fields - do you discuss ordinal methods in depth? The Liddell and Kruschke paper? (Analyzing ordinal data with metric models: What could possibly go wrong?) What do you recommend to students who often use ordinal outcomes? #statssky
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Darren Dahly @statsepi.bsky.social · 13/11/2025
Nice one, from @drg.bsky.social and @jamesheathers.bsky.social link.springer.com/article/10.1...
link.springer.com
“Cake causes herpes?” - promiscuous dichotomisation induces false positives - BMC Medical Research Methodology
Background Continuous biomedical data is often dichotomized into two or more groups for analysis, despite long-standing warnings from statisticians that this constitutes bad practice. This dichotomisa...
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Dan Lewer @danlewer.bsky.social · 27/10/2025
We wrote an article explaining why you shouldn't put several variables into a regression model and report which are statistically significant - even as exploratory research. bmjmedicine.bmj.com/content/4/1/.... How did we do?
A "methods primer" article in the journal "BMJ Medicine", titled "Factors associated with: problems of using exploratory multivariable regression to identify causal risk factors"
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Richard McElreath 🐈‍⬛ @rmcelreath.bsky.social · 23/10/2025
Monty Python understood p-hacking
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Claus Wilke @clauswilke.com · 22/10/2025
We need to have a conversation about random seeds. Don't use 42. blog.genesmindsmachines.com/p/if-your-ra...
blog.genesmindsmachines.com
If your random seed is 42 I will come to your office and set your computer on fire🔥
Figuratively. More likely you'll get a stern talking to.
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Rob Cavanaugh @rbcavanaugh.bsky.social · 22/10/2025
Any #rstats folks know the differences in lme4::glmer()'s specification for aggregated binomials? (or reading rec's?) I'd like to confirm my understanding of these: cbind(successes, failures) ~ ... successes/trials ~ ..., weights = trials successes/trials ~ ..., weights = NULL (or unspecified)
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Maëlle Salmon @masalmon.eu · 23/09/2025
"How I, a non-developer, read the tutorial you, a developer, wrote for me, a beginner" by Annie Mueller 😅 😂 😭 anniemueller.com/posts/how-i-...
anniemueller.com
How I, a non-developer, read the tutorial you, a developer, wrote for me, a beginner - annie's blog
“Hello! I am a developer. Here is my relevant experience: I code in Hoobijag and sometimes jabbernocks and of course ABCDE++++ (but never ABCDE+/^+ are you kidding? ha!)  and I like working with ...
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Swathi Kiran@Center for Brain Recovery at BU @swathikiran.bsky.social · 03/09/2025
Join us Monday, September 15th from 4:00 pm to 5:00 pm ET for a talk by Simona Mancini, Ikerbasque Research Associate Professor / Neurolinguistics and Aphasia group leader at the Basque Center on Cognition Brain and Language. Register now at bit.ly/45LjrF1
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Julia M. Rohrer @dingdingpeng.the100.ci · 25/08/2025
Ever stared at a table of regression coefficients & wondered what you're doing with your life? Very excited to share this gentle introduction to another way of making sense of statistical models (w @vincentab.bsky.social) Preprint: doi.org/10.31234/osf... Website: j-rohrer.github.io/marginal-psy...
Models as Prediction Machines: How to Convert Confusing Coefficients into Clear Quantities

Abstract
Psychological researchers usually make sense of regression models by interpreting coefficient estimates directly. This works well enough for simple linear models, but is more challenging for more complex models with, for example, categorical variables, interactions, non-linearities, and hierarchical structures. Here, we introduce an alternative approach to making sense of statistical models. The central idea is to abstract away from the mechanics of estimation, and to treat models as “counterfactual prediction machines,” which are subsequently queried to estimate quantities and conduct tests that matter substantively. This workflow is model-agnostic; it can be applied in a consistent fashion to draw causal or descriptive inference from a wide range of models. We illustrate how to implement this workflow with the marginaleffects package, which supports over 100 different classes of models in R and Python, and present two worked examples. These examples show how the workflow can be applied across designs (e.g., observational study, randomized experiment) to answer different research questions (e.g., associations, causal effects, effect heterogeneity) while facing various challenges (e.g., controlling for confounders in a flexible manner, modelling ordinal outcomes, and interpreting non-linear models).
Figure illustrating model predictions. On the X-axis the predictor, annual gross income in Euro. On the Y-axis the outcome, predicted life satisfaction. A solid line marks the curve of predictions on which individual data points are marked as model-implied outcomes at incomes of interest. Comparing two such predictions gives us a comparison. We can also fit a tangent to the line of predictions, which illustrates the slope at any given point of the curve.A figure illustrating various ways to include age as a predictor in a model. On the x-axis age (predictor), on the y-axis the outcome (model-implied importance of friends, including confidence intervals).

Illustrated are 
1. age as a categorical predictor, resultings in the predictions bouncing around a lot with wide confidence intervals
2. age as a linear predictor, which forces a straight line through the data points that has a very tight confidence band and
3. age splines, which lies somewhere in between as it smoothly follows the data but has more uncertainty than the straight line.
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Solomon Kurz @solomonkurz.bsky.social · 21/07/2025
New #rstats blog up! solomonkurz.netlify.app/blog/2025-07... This is the first in a new series discussing causal inference with experimental data using multilevel models. My basic case is g-computation is the way to go.
solomonkurz.netlify.app
Within-person factorial experiments, log(normal) reaction-time data | A. Solomon Kurz
Causal inference with the GLMM, Part 1
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Richard McElreath 🐈‍⬛ @rmcelreath.bsky.social · 09/07/2025
How can we reform science? I have some ideas. But I am not sure you’ll like them, because they don’t promise much. elevanth.org/blog/2025/07...
elevanth.org
Which Kind of Science Reform
What hope is there for science reform, if we can't agree on what to reform? Right now, principles are more important than practices.
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Brielle Stark, PhD {she} @briellestark.bsky.social · 08/04/2025
Had a great time sharing about our test-retest, #multimodal #communication #aphasia & peer dataset at the University of Technology Sydney Graduate School of Health seminar series today. Join AphasiaBank (totally free) and get full access to our data! aphasia.talkbank.org/access/Engli...
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Jeremy Berg @jeremymberg.bsky.social · 29/03/2025
Funding curves for K and F mechanisms (Warning: the new F mechanism "curve" is a lot)
media.tenor.com
a cartoon of homer simpson holding a card
ALT: a cartoon of homer simpson holding a card
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Rob Cavanaugh @rbcavanaugh.bsky.social · 26/03/2025
Hey #rstats friends. I’m looking for examples of papers or posts that do a really really good job unpacking/writing about/explaining statistical results. Not just technically correct but also clear. Bonus points for using marginal effects. What’s your go to exemplar for students new to research?
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Julia M. Rohrer @dingdingpeng.the100.ci · 20/03/2025
New blog post! In which I explain the issue with mediation analysis and sketch out one way to deal with the underlying causal inference problem -- in just a bit over 1,000 words! If you have never found the time to read up on this, now is your chance. www.the100.ci/2025/03/20/r...
the100.ci
Reviewer notes: That’s a very nice mediation analysis you have there. It would be a shame if something happened to it.
Mediation analysis has gotten a lot of flak, including classic titles such as “Yes, but what’s the mechanism? (Don’t expect an easy answer)” (Bullock et al., 2010), “What mediation analysis can (not) ...
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Rob Cavanaugh @rbcavanaugh.bsky.social · 07/03/2025
Bsky/Academia friends - any suggestions on time tracking software? Criteria: I want to spend as little time as possible actually tracking my time. Bonus if integrated with outlook. Doesn’t need to be exact. I’m just hoping for a reasonable estimate of research/teaching/service breakdown.
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Aidan Wright @aidangcw.bsky.social · 25/02/2025
NIH cuts are getting the press, but VA research is getting slashed too. What do we lose when VA research goes away? Here's some greatest hits: The nicotine patch, invention of the cardiac pacemaker, first successful liver transplant, development of the CAT/CT scan prospect.org/health/2025-...
prospect.org
VA Research Funding Slashed
Though not as prominent as the NIH, VA researchers play a major role in advancing basic health science. Hundreds of projects have been cut.
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Jen Jennings @jenjennings.bsky.social · 21/02/2025
DEI initiatives are still legal. Universities need to stand their ground. A Friday gift to your university's General Counsel Office - courtesy of an all star lineup of civil rights lawyers and scholars. You're going to want to read this.
app.box.com
OGC Memo re Trump DEI and SFFA 2025 02 20.pdf | Powered by Box
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Julia M. Rohrer @dingdingpeng.the100.ci · 17/02/2025
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...
the100.ci
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...
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Russ Poldrack @russpoldrack.org · 08/02/2025
Great analysis of the indirect cost rate announcement by @stuartbuck.bsky.social
open.substack.com
Indirect Costs at NIH . . .
I wasn’t planning on spending part of a Saturday writing about cost accounting principles and the like, but NIH-world was hit with a doozy of a policy announcement on Friday night:
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Rachel Ryskin @ryskin.bsky.social · 06/02/2025
🚨 New open-access paper out now in PB&R: link.springer.com/article/10.3... We (w/ Ted Gibson, @swathikiran.bsky.social) explore how individuals with aphasia interpret sentences & whether their comprehension difficulties stem from increased expectations of noise in language input. 🧵👇
link.springer.com
Noisy-channel language comprehension in aphasia: A Bayesian mixture modeling approach - Psychonomic Bulletin & Review
Individuals with “agrammatic” receptive aphasia have long been known to rely on semantic plausibility rather than syntactic cues when interpreting sentences. In contrast to early interpretations of th...
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Rob Cavanaugh @rbcavanaugh.bsky.social · 16/01/2025
In case anyone is wondering, I did ask GPT and I don’t think it quite has a handle on DAGs yet.
A very convoluted “DAG” that breaks lots of DAG rules and has lots of spelling errors
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Rob Cavanaugh @rbcavanaugh.bsky.social · 16/01/2025
Question for #rstats / #causalinference friends. I can imagine the DAG for a basic RCT and a model: PostTx ~ Group + PreTx Does the DAG change for the repeated measures equivalent? Score ~ Time (pre/post) + Group + Time (pre/post) x Group (And what if there's a prognostic variable to be added??)
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Mattan S. Ben-Shachar @mattansb.msbstats.info · 06/01/2025
Hey #StatsSky, what are you favorite papers to cite when you need to justify something that is obvious (I once had a reviewer ask we justify the use of logistic regression on a binary outcome) or when you need to push-back on silly reviewer requests (e.g., asking for p-values in table 1)?
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Sam Harvey @samharveyaphasia.bsky.social · 10/12/2024
The Aphasia Therapy Finder is a free online tool to help speech therapists find and access high quality resources and instructional videos for evidence-based aphasia therapies. If you haven’t already, please check it out and share widely.
This is a flyer for the Aphasia Therapy Finder. The Aphasia Therapy Finder is a free online tool to help speech therapists find and access high quality resources and instructional videos for evidence-based aphasia therapies.
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Julia M. Rohrer @dingdingpeng.the100.ci · 05/12/2024
New post on the 100% Christmas Interval -- after almost 8 years, it's time that we finally talk about CIs. www.the100.ci/2024/12/05/w...
the100.ci
Why you are not allowed to say that your 95% confidence interval contains the true parameter with a probability of 95%
A shibboleth is a custom, such as a choice of phrasing, that distinguishes one group of people from another. The term goes back to the Hebrew Bible, in which the inhabitants of Gilead identify members...
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Brielle Stark, PhD {she} @briellestark.bsky.social · 20/11/2024
FOQUSAphasia will be kicking off structured #writing groups again in January! Pop over to the website to learn more about our consortium on #discourse in #aphasia (broadly defined!) and register your interest. Can't wait to see you! www.foqusaphasia.com/writinggroup
foqusaphasia.com
Writing Groups | My Site
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Brielle Stark, PhD {she} @briellestark.bsky.social · 26/11/2024
Just stumbled on this and stoked to use it for future research! pubs.asha.org/doi/abs/10.1...
pubs.asha.org
Picturing Better Materials: Normative Data on a Novel Illustration Set for Scientific and Clinical Use
Purpose: Picture stimuli are essential materials for language research and clinical practice. Here, we generated a modern, full-color set of 310 ...
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John E Pierce @jepierce.bsky.social · 26/11/2024
Register to hear 45 minutes of wisdom from the fantastic aphasia trialist, Caterina Breitenstein - *tomorrow* Wednesday 27th November 👂📝 (Alternatively, catch up on our youtube channel) t.co/ShMY0YBstj #aphasia
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Andrew Heiss @andrew.heiss.phd · 22/11/2024
From the archives: Have you (like me!) wondered what the ATT means and how it's different from average treatment effects? I use #rstats to explore why we care about (and how to calculate) the ATE, ATT, and ATU #polisky #episky #econsky www.andrewheiss.com/blog/2024/03...
Mirrored histogram showing “weird” parts of the population: treated people who were unlikely to be treated, and untreated people who were likely to be treatedMirrored histogram showing pseudo-populations of treated and untreated people that have been reweighted to be more comparable and unconfoundedTable showing potential and realized outcomes for 9 simulated people Before we calculate these different treatment effects with the realized outcomes instead of the hypothetical potential outcomes, let's look really quick at the practical difference between the true ATE, AT 1, and ATU. All three estimands are useful for policymaking!
The ATE is -15, implying that mosquito nets cause a 15 point reduction in malaria risk for every person in the country. This includes people who live at high elevations where mosquitoes don't live, people who live near mosquito-infested swamps, people who are rich enough to buy Bill Gates's mosquito laser, and people who can't afford a net but would really like to use one. If we worked in the Ministry of Health and wanted to know if we should make a new national program that gave everyone a free bed net, the overall reduction in risk is -15, which is probably pretty good!
The ATT is -16.29, which is bigger than the ATE. The effect of net usage is bigger for people who are already using the nets. This is because of underlying systematic reasons, or selection bias. Those using nets want to use them because they need them more or can access them more easily-they might live in areas more prone to mosquitoes, or they can afford to buy their own nets, or something else. They know themselves and understand some notion of their personal individual causal effect and seek out nets. If we removed access to their nets, it would have a strong effect.
The ATU is -13.63, which is smaller than the ATE. The effect of net usage is smaller for people who aren't using the nets. Again, this is because of selection bias. Those not using nets are likely not using them for systematic reasons-they live far away from mosquitoes, they've received a future malaria vaccine, they have some other form of mosquito abatement, or something else. Because they can read their own minds, they know that mosquito net use won't do much for them personally, so they don't seek out nets. If we expanded access to nets to them, they wouldn't benefit
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A/Prof Sarah J. Wallace @sarahjwallace.bsky.social · 21/11/2024
The Aphasia Research Library www.aphasialibrary.org is a new, free resource for creating and sharing aphasia friendly research summaries. Co-designed with people living with aphasia and researchers. Learn more here: www.dropbox.com/scl/fi/xais8...
Image describing features of the Aphasia Research Library www.aphasialibrary.org
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Brielle Stark, PhD {she} @briellestark.bsky.social · 18/11/2024
A goal of mine for MANY YEARS has been to make plain language summaries and, where possible, #infographics of the papers coming out of the lab. Thanks to awesome undergrad RAs, here they come! Check back in as more get added! #aphasia #accessible #research www.neuralresearchlab.com/plainlang
neuralresearchlab.com
Accessible Research — NEURAL Research Lab
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Brielle Stark, PhD {she} @briellestark.bsky.social · 17/11/2024
Join the #aphasia cohort on BSky! go.bsky.app/PW5JHmQ
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Jonathan Peelle @jpeelle.bsky.social · 11/11/2024
Here's a starter pack for people interested in the cognitive science and neuroscience of language. With all the new Bluesky arrivals, I'm sure I'm missing people—please let me know and I'll add! go.bsky.app/6iumPee
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Darren Dahly @statsepi.bsky.social · 12/11/2024
In clinical research, you will often receive feedback on study design, stats, and/or data analysis from an editor or reviewer that is simply wrong. Here is a list of common "statistical myths" and references you can use to push back. discourse.datamethods.org/t/reference-...
discourse.datamethods.org
Reference Collection to push back against "Common Statistical Myths"
Note: This topic is a wiki, meaning that this main body of the topic can be edited by others. Use the Reply button only to post questions or comments about material contained in the body, or to sugge...
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Demetri @phdemetri.bsky.social · 31/10/2024
My posit conf talk is live youtu.be/sjYNUIkOlC0?...
youtu.be
Making sense of marginal effects - posit conf 2024
YouTube video by Posit PBC
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Paul Bürkner @paulbuerkner.com · 30/10/2024
brms book update: I have added a new chapter on generalized linear multilevel models (GLMMs). See paulbuerkner.com/software/brm... for the latest draft of the book. I would love to hear your thoughts!
paulbuerkner.com
Paul Bürkner - The brms Book
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