Simen Leithe Tajet
@tajet.bsky.social
PHD student at the Norwegian school of sports science
Reposted by Simen Leithe Tajet
This smells distinctly like collider bias and/or selection bias and/or regression to the mean... You simply can't select teen prodigies, and world class athletes rom databases, and go run regressions without serious consideration of the selection process!
"Most top achievers (Nobel laureates and world-class musicians, athletes, chess players) demonstrated lower performance than many peers during their early years. Across the highest adult performance, peak performance is negatively correlated with early performance" www.science.org/doi/10.1126/...
Recent discoveries on the acquisition of the highest levels of human performance
Scientists have long debated the origins of exceptional human achievements. This literature review summarizes recent evidence from multiple domains on the acquisition of world-class performance. We re...
www.science.org
December 20, 2025 at 3:48 PM
This smells distinctly like collider bias and/or selection bias and/or regression to the mean... You simply can't select teen prodigies, and world class athletes rom databases, and go run regressions without serious consideration of the selection process!
Reposted by Simen Leithe Tajet
Updatedletter, I know go into soem emperical results as well: zenodo.org/records/1800...
The Apperent Negative Associations Between Early and Adult Performance in elite performers Arise from Colider Selection Bias and Baserate Neglect
Güllich et al. argue that among elite performers there is a negative association between early and adult performance, a pattern they link to distinct developmental causal mechanisms for early, and adu...
zenodo.org
December 21, 2025 at 12:01 PM
Updatedletter, I know go into soem emperical results as well: zenodo.org/records/1800...
Reposted by Simen Leithe Tajet
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...
I will record lectures & all will be found at this link: github.com/rmcelreath/s...
December 9, 2025 at 1:58 PM
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...
I will record lectures & all will be found at this link: github.com/rmcelreath/s...
Reposted by Simen Leithe Tajet
I think almost all scientific projects should be planned carefully. And I think an app can dramatically improve that. So I wrote an app for that (free for now, if you can fund this let me know). I tested it quite a bit (>8000 users in beta so far). try it: planyourscience.com
November 20, 2025 at 3:33 PM
I think almost all scientific projects should be planned carefully. And I think an app can dramatically improve that. So I wrote an app for that (free for now, if you can fund this let me know). I tested it quite a bit (>8000 users in beta so far). try it: planyourscience.com
Reposted by Simen Leithe Tajet
New blog post! ”Which variables to control for, and why”: pedermisager.org/blog/which-v...
In this post I give a beginner-friendly introduction to causal inference and statistical control, explaining why adjusting for the right variables clarifies relationships >
In this post I give a beginner-friendly introduction to causal inference and statistical control, explaining why adjusting for the right variables clarifies relationships >
Which variables to control for, and why | Peder M. Isager
Personal website of Dr. Peder M. Isager
pedermisager.org
November 17, 2025 at 3:00 PM
New blog post! ”Which variables to control for, and why”: pedermisager.org/blog/which-v...
In this post I give a beginner-friendly introduction to causal inference and statistical control, explaining why adjusting for the right variables clarifies relationships >
In this post I give a beginner-friendly introduction to causal inference and statistical control, explaining why adjusting for the right variables clarifies relationships >
Reposted by Simen Leithe Tajet
Our paper on improving statistical reporting in psychology is now online 🎉
As a part of this paper, we also created the Transparent Statistical Reporting in Psychology checklist, which researchers can use to improve their statistical reporting practices
www.nature.com/articles/s44...
As a part of this paper, we also created the Transparent Statistical Reporting in Psychology checklist, which researchers can use to improve their statistical reporting practices
www.nature.com/articles/s44...
November 14, 2025 at 8:43 PM
Our paper on improving statistical reporting in psychology is now online 🎉
As a part of this paper, we also created the Transparent Statistical Reporting in Psychology checklist, which researchers can use to improve their statistical reporting practices
www.nature.com/articles/s44...
As a part of this paper, we also created the Transparent Statistical Reporting in Psychology checklist, which researchers can use to improve their statistical reporting practices
www.nature.com/articles/s44...
Reposted by Simen Leithe Tajet
There still seems to be a lot of confusion about significance testing in psych. No, p-values *don’t* become useless at large N. This flawed point also used to be framed as "too much power". But power isn't the problem – it's 1) unbalanced error rates and 2) the (lack of a) SESOI. 1/ >
October 31, 2025 at 8:13 AM
There still seems to be a lot of confusion about significance testing in psych. No, p-values *don’t* become useless at large N. This flawed point also used to be framed as "too much power". But power isn't the problem – it's 1) unbalanced error rates and 2) the (lack of a) SESOI. 1/ >
Reposted by Simen Leithe Tajet
Are you interested in thinking about which studies are worth replicating? Then you have 10 articles to dig into in Meta-Psychology, representing a very wide range of viewpoint on this topic, out now: open.lnu.se/index.php/me...
LnuOpen
| Meta-Psychology
Original articles
open.lnu.se
October 30, 2025 at 3:43 PM
Are you interested in thinking about which studies are worth replicating? Then you have 10 articles to dig into in Meta-Psychology, representing a very wide range of viewpoint on this topic, out now: open.lnu.se/index.php/me...
Reposted by Simen Leithe Tajet
New Pre-Print:
www.biorxiv.org/cgi/content/...
We’re all familiar with having to practice a new skill to get better at it, but what really happens during practice? The answer, I propose, is reinforcement learning - specifically policy-gradient reinforcement learning.
Overview 🧵 below...
www.biorxiv.org/cgi/content/...
We’re all familiar with having to practice a new skill to get better at it, but what really happens during practice? The answer, I propose, is reinforcement learning - specifically policy-gradient reinforcement learning.
Overview 🧵 below...
Policy-Gradient Reinforcement Learning as a General Theory of Practice-Based Motor Skill Learning
Mastering any new skill requires extensive practice, but the computational principles underlying this learning are not clearly understood. Existing theories of motor learning can explain short-term ad...
www.biorxiv.org
October 20, 2025 at 2:58 PM
New Pre-Print:
www.biorxiv.org/cgi/content/...
We’re all familiar with having to practice a new skill to get better at it, but what really happens during practice? The answer, I propose, is reinforcement learning - specifically policy-gradient reinforcement learning.
Overview 🧵 below...
www.biorxiv.org/cgi/content/...
We’re all familiar with having to practice a new skill to get better at it, but what really happens during practice? The answer, I propose, is reinforcement learning - specifically policy-gradient reinforcement learning.
Overview 🧵 below...
Reposted by Simen Leithe Tajet
Against Publishing: universonline.nl/nieuws/2025/...
Preprints are read, shared, and cited, yet still dismissed as incomplete until blessed by a publisher. I argue that the true measure of scholarship lies in open exchange, not in the industry’s gatekeeping of what counts as published.
Preprints are read, shared, and cited, yet still dismissed as incomplete until blessed by a publisher. I argue that the true measure of scholarship lies in open exchange, not in the industry’s gatekeeping of what counts as published.
October 14, 2025 at 9:16 AM
Against Publishing: universonline.nl/nieuws/2025/...
Preprints are read, shared, and cited, yet still dismissed as incomplete until blessed by a publisher. I argue that the true measure of scholarship lies in open exchange, not in the industry’s gatekeeping of what counts as published.
Preprints are read, shared, and cited, yet still dismissed as incomplete until blessed by a publisher. I argue that the true measure of scholarship lies in open exchange, not in the industry’s gatekeeping of what counts as published.
First PhD paper out as preprint!
Through 24 interviews with elite alpine skiers and coaches, I examined how video visualization works in practice and what future technologies might offer.
sportrxiv.org/index.php/se...
Through 24 interviews with elite alpine skiers and coaches, I examined how video visualization works in practice and what future technologies might offer.
sportrxiv.org/index.php/se...
Beyond Visualization: Elite Alpine Skiers and Coaches' Insights into Simulation Training
| SportRxiv
sportrxiv.org
October 14, 2025 at 10:43 AM
First PhD paper out as preprint!
Through 24 interviews with elite alpine skiers and coaches, I examined how video visualization works in practice and what future technologies might offer.
sportrxiv.org/index.php/se...
Through 24 interviews with elite alpine skiers and coaches, I examined how video visualization works in practice and what future technologies might offer.
sportrxiv.org/index.php/se...
Reposted by Simen Leithe Tajet
How many years after undergrad stats did you discover that common statistical tests are linear models? lindeloev.github.io/tests-as-lin...
August 7, 2025 at 10:35 AM
How many years after undergrad stats did you discover that common statistical tests are linear models? lindeloev.github.io/tests-as-lin...
Reposted by Simen Leithe Tajet
Excellent new preprint by Sarahanne Field and @maddipow.bsky.social argues “bias is not a contaminant to be purged; it is a constitutive element of research, shaping every decision from hypothesis formation to data interpretation.”
Few quotes follow...🧵
Few quotes follow...🧵
"Science is not, and has never been, a neutral endeavour... the notion that researchers can or should cleanse themselves of bias is untenable, potentially intellectually dishonest, and ethically fraught."
New preprint with the (brilliant) Sarahanne Field #Metascience2025
osf.io/preprints/os...
New preprint with the (brilliant) Sarahanne Field #Metascience2025
osf.io/preprints/os...
July 2, 2025 at 3:41 PM
Excellent new preprint by Sarahanne Field and @maddipow.bsky.social argues “bias is not a contaminant to be purged; it is a constitutive element of research, shaping every decision from hypothesis formation to data interpretation.”
Few quotes follow...🧵
Few quotes follow...🧵
Reposted by Simen Leithe Tajet
The journal of Sports and Sciences will now require mandatory sample size estimation and justification www.tandfonline.com/doi/full/10.... This is an excellent step that will improve scientific papers. I expect many other journals will follow.
Sample size estimation revisited
Published in Journal of Sports Sciences (Ahead of Print, 2025)
www.tandfonline.com
May 7, 2025 at 6:42 PM
The journal of Sports and Sciences will now require mandatory sample size estimation and justification www.tandfonline.com/doi/full/10.... This is an excellent step that will improve scientific papers. I expect many other journals will follow.
Reposted by Simen Leithe Tajet
I've now uploaded this to a new youtube channel too.
I may look to upload other content over time, including some of my old research methods videos.
I may look to upload other content over time, including some of my old research methods videos.
May 6, 2025 at 7:20 PM
I've now uploaded this to a new youtube channel too.
I may look to upload other content over time, including some of my old research methods videos.
I may look to upload other content over time, including some of my old research methods videos.
Reposted by Simen Leithe Tajet
New paper: Blaming the Thermometer for the Fever: Separating Misapplication from Method in Null Hypothesis Significance Testing, with @laabho.bsky.social and @jnwulff.bsky.social. We – strongly – push back on criticisms against NHST and argue for proper application. papers.ssrn.com/sol3/papers.... >
Blaming the Thermometer for the Fever: Separating Misapplication from Method in Null Hypothesis Significance Testing
In empirical research, Null Hypothesis Significance Testing (NHST) is the most common methodology to interpret research findings and make inferences, particular
papers.ssrn.com
April 23, 2025 at 5:55 AM
New paper: Blaming the Thermometer for the Fever: Separating Misapplication from Method in Null Hypothesis Significance Testing, with @laabho.bsky.social and @jnwulff.bsky.social. We – strongly – push back on criticisms against NHST and argue for proper application. papers.ssrn.com/sol3/papers.... >
Reposted by Simen Leithe Tajet
I created this reading list on theory in psychology a while back, so it probably needs an update! Would love any recommendations for papers to include – maybe I can turn this into a syllabus of sorts.
PDF of this reading list here: williamngiam.github.io/reading_list...
PDF of this reading list here: williamngiam.github.io/reading_list...
April 24, 2025 at 1:23 PM
I created this reading list on theory in psychology a while back, so it probably needs an update! Would love any recommendations for papers to include – maybe I can turn this into a syllabus of sorts.
PDF of this reading list here: williamngiam.github.io/reading_list...
PDF of this reading list here: williamngiam.github.io/reading_list...
Reposted by Simen Leithe Tajet
New paper by former lab visitor Max Ditroilo, "Exploratory research in sport and exercise science". We propose narrower definitions where hypothesis tests are confirmatory when error rates are controlled, and exploratory when not, and give reporting advice. www.tandfonline.com/doi/full/10....
April 8, 2025 at 2:14 PM
New paper by former lab visitor Max Ditroilo, "Exploratory research in sport and exercise science". We propose narrower definitions where hypothesis tests are confirmatory when error rates are controlled, and exploratory when not, and give reporting advice. www.tandfonline.com/doi/full/10....
Reposted by Simen Leithe Tajet
The latest from myself, @crist14n.bsky.social, Grant Abt, and @lakens.bsky.social on exploratory research in sport/exercise science.
doi.org/10.1080/0264...
We outline the differences between exploratory & confirmatory studies and best practice for conducting/reporting an exploratory study.
doi.org/10.1080/0264...
We outline the differences between exploratory & confirmatory studies and best practice for conducting/reporting an exploratory study.
Exploratory research in sport and exercise science: Perceptions, challenges, and recommendations
Quantitative exploratory research implies a flexible examination of a dataset with the purpose of finding patterns, associations, and interactions between variables to help formulate a hypothesis, ...
doi.org
April 9, 2025 at 9:15 AM
The latest from myself, @crist14n.bsky.social, Grant Abt, and @lakens.bsky.social on exploratory research in sport/exercise science.
doi.org/10.1080/0264...
We outline the differences between exploratory & confirmatory studies and best practice for conducting/reporting an exploratory study.
doi.org/10.1080/0264...
We outline the differences between exploratory & confirmatory studies and best practice for conducting/reporting an exploratory study.
Reposted by Simen Leithe Tajet
I'll finally get to teach a workshop on one of my favourite subjects - causal inference - at the Paul Meehl graduate school may 9th! Ever wondered what the point is of controlling for variables in your regression analysis? Come find out with us!
A new free workshop of the Paul Meehl Graduate School is open for registration! On May 9 @isager.bsky.social will teach on Causal Inference and Variable Control. Check out the announcement below, and see you all @tue.nl!
paulmeehlschool.github.io/2025-04-02-c...
paulmeehlschool.github.io/2025-04-02-c...
New workshop announced: Causal Inference and Variable Control | Paul meehl Graduate School
We are excited to announce that registration is now open for the workshop “Causal Inference and Variable Control”. In this...
paulmeehlschool.github.io
April 3, 2025 at 4:35 PM
I'll finally get to teach a workshop on one of my favourite subjects - causal inference - at the Paul Meehl graduate school may 9th! Ever wondered what the point is of controlling for variables in your regression analysis? Come find out with us!
Reposted by Simen Leithe Tajet
11 years ago, I thought R was unnecessary. Now, I can’t imagine life without it. The switch wasn’t easy, but it made me a better scientist.
You can read my journey here: mattkmiecik.substack.com/p/my-start-w...
#rstats #DataScience #OpenScience
You can read my journey here: mattkmiecik.substack.com/p/my-start-w...
#rstats #DataScience #OpenScience
My start with R
The programming language that made me a better scientist
mattkmiecik.substack.com
March 30, 2025 at 3:10 PM
11 years ago, I thought R was unnecessary. Now, I can’t imagine life without it. The switch wasn’t easy, but it made me a better scientist.
You can read my journey here: mattkmiecik.substack.com/p/my-start-w...
#rstats #DataScience #OpenScience
You can read my journey here: mattkmiecik.substack.com/p/my-start-w...
#rstats #DataScience #OpenScience
Reposted by Simen Leithe Tajet
This is an interesting essay by @draehernandez.bsky.social. The cognitive training/skill acquisition literature suggests that the effect of practice is often highly specific, but this essay argues that some practice effects (perseverance in the face of adversity) may transfer to other life domains.
March 27, 2025 at 12:51 AM
This is an interesting essay by @draehernandez.bsky.social. The cognitive training/skill acquisition literature suggests that the effect of practice is often highly specific, but this essay argues that some practice effects (perseverance in the face of adversity) may transfer to other life domains.
Reposted by Simen Leithe Tajet
Had a lot of fun getting to talk philosophy of science, myths, theories, severe testing etc. in exercise science on the Iron Culture
Ep 320 - Myths Versus Theories in Exercise Science (ft. James Steele)
YouTube video by Iron Culture Podcast
www.youtube.com
March 25, 2025 at 8:15 AM
Had a lot of fun getting to talk philosophy of science, myths, theories, severe testing etc. in exercise science on the Iron Culture
Reposted by Simen Leithe Tajet
Adding to the intro chapter the coffee cup example I'd always use when I was teaching (usually because I was pacing the room holding my coffee cup 😅) to explain Bhaskar's empirical/actual/causal realms distinction.
March 23, 2025 at 11:13 AM
Adding to the intro chapter the coffee cup example I'd always use when I was teaching (usually because I was pacing the room holding my coffee cup 😅) to explain Bhaskar's empirical/actual/causal realms distinction.
Reposted by Simen Leithe Tajet
The trend of sport and exercise scientists, a field of largely statistically illiterate researchers (not all, but most), eschewing hypothesis testing (mostly NHST) for estimation approaches (i.e., confidence intervals) has seemingly licenced most to just interpret the sign of their effect estimate.
March 19, 2025 at 4:49 PM
The trend of sport and exercise scientists, a field of largely statistically illiterate researchers (not all, but most), eschewing hypothesis testing (mostly NHST) for estimation approaches (i.e., confidence intervals) has seemingly licenced most to just interpret the sign of their effect estimate.