Christian Magelssen
cmagelssen.bsky.social
Christian Magelssen
@cmagelssen.bsky.social
PhD in (motor) skill learning | www.christianmagelssen.com
Reposted by Christian Magelssen
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.
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
Reposted by Christian Magelssen
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
Reposted by Christian Magelssen
Here's a draft of the second chapter I have been writing on research activities including theory building, testing, and applied/technological research:

bit.ly/research_act...

A 🧵 on why I am sharing this now...
Dropbox
bit.ly
January 11, 2025 at 12:15 PM
How can we train skills effectively? 🧠

That was the topic when I joined Olympiatoppen’s podcast yesterday, where I discussed this with Caper Ruud’s technical coach, Øivind Sørvald. #tennis #sport #motorlearning #skillearning
February 27, 2025 at 8:35 PM
Reposted by Christian Magelssen
We grumbled while presiding over a rotten system. Now the grumbling has been weaponised to ruin the system completely. I think this goes beyond science.
People have already blamed science reform for what is happening.

For 15 years I have said: If we do not get our shit together (less publication bias, higher quality, more coordination) someone else is going to implement change top down, and we are not going to like how they do it.

And here we are.
February 19, 2025 at 8:09 AM
Reposted by Christian Magelssen
30. principles of sensorimotor control

up to now, we've mostly talked about how brains construct internal representations of the world. now let's talk about how we use those representations to act on the world, through motor output.

movement feels natural to us, but our brains are doing a lot.
February 9, 2025 at 10:01 AM
Reposted by Christian Magelssen
We have a great program lined up for NCM 2025 in Panama! Poster submissions are open until Feb 17th. #NCMPan25
The #NCMPan25 program is now available! Review the talks, panels, and more and make your plans for Panama.
January 30, 2025 at 7:41 PM
Reposted by Christian Magelssen
Reposting this for the weekday crowd

A new YouTube video on one of the new functions in my gratia 📦 for #RStats
I've posted a new video on YouTube that gives a brief overview of the new conditional_values() function in my gratia #RStats 📦

I plan to do more of these videos over the next few weeks & months. Make sure you're subscribed if you want to be notified as they get posted.
youtu.be/iKG0aHWpTAo
Visualizing generalized additive models in R using gratia and conditional_values()
YouTube video by Bottom of the Heap
youtu.be
January 27, 2025 at 11:09 AM
Hello! My name is Christian Magelssen, and I hold a PhD focused on (motor) skill learning in elite alpine skiers. I’m looking to take the next step and would love to get some advice from people I admire and think might have answers to my questions. (1/5)
January 22, 2025 at 11:58 AM
Reposted by Christian Magelssen
How do people shoot pucks at targets for money?

In this new preprint based on work led by @fatatai.bsky.social together with @c-rothkopf.bsky.social, we show that they take an internal physics model and their individual sensorimotor variability into account.
Hello Bluesky,
with my first post, I would like to announce that my first first-author paper is out now!

Have you ever wondered whether people account for Newtonian physics when interacting with objects?

Together with @dominikstrb.bsky.social and @c-rothkopf.bsky.social we show that they do!
January 16, 2025 at 10:49 AM
I’ve built a simple website for anyone interested in following my projects! 🎉

cmagelssen.github.io/portfolio/

I’m planning to create tutorials on skill learning and/or stats with React & D3.js in the future.

I’d love to hear your thoughts, discuss ideas, or get feedback. Thanks! 🙏
Christian Magelssen - Personal website
cmagelssen.github.io
January 14, 2025 at 6:32 PM
I have a preprint of a study I’m not proud of and honestly don’t have the energy to submit to a journal. Still, I hope it reaches those considering using the same technology to study alpine skiin. In this case, the technology overshadowed the research question—and that’s always a recipe for failure.
January 13, 2025 at 7:46 PM
Reposted by Christian Magelssen
It's tool and website maintenance day! I am aiming to:

1. finally get faux resubmitted to CRAN
2. update the @psyteachr.bsky.social site
3. automate a few things for recognition.ukrn-openresearch.ac.uk
4. update my intro to #rstats packages workshop psyteachr.github.io/intro-r-pkgs/
January 13, 2025 at 11:08 AM
I will defend my PhD on December 19th! The title of my thesis is "Improving teaching and movement strategies for skill learning and performance in skilled and elite alpine ski racers" The defence is open to everyone and can be followed live. More info here: www.nih.no/om/aktuelt/h...
Disputas: Undervisnings- og bevegelsesstrategier for å lære og forbedre ferdigheter hos alpinister - Norges idrettshøgskole
Utøvere som lærer valg av strategier gjennom prøving og feiling, lærer og presterer sammenlignet med tradisjonell instruksjonsbasert læring, viser forskning gjort på 98 alpinister.
www.nih.no
December 4, 2024 at 7:33 PM
Hi #sensorimotor, how would you define supervised learning in motor learning? This has been one of my biggest headaches during my PhD. It might have to do with the that it operates on different levels depending on whether one looks at the selection of actions or the execution of actions.
November 29, 2024 at 8:21 PM
Reposted by Christian Magelssen
Hyggelig å kunne oppdatere denne go.bsky.app/HMj7aqg, spesielt med @unioslo.bsky.social
November 21, 2024 at 10:11 AM
Reposted by Christian Magelssen
Really great to see this recommended in @pci-hms.bsky.social after all Hannah's hard work. Also a great review process with @mbieleke.bsky.social and the other reviewer really helping improve and tighten up the manuscript, thanks! 🙏
New peer-reviewed preprint by Corcoran H. & @jamessteeleii.bsky.social: Cumulative evidence synthesis and consideration of "research waste" using Bayesian methods.

Recommended by @wanjawolff.bsky.social & Gaveau J. for
@pci-hms.bsky.social. Reviews by @mbieleke.bsky.social.
doi.org/10.24072/pci...
November 20, 2024 at 7:26 PM
My doctoral thesis has been approved, and I will defend it on December 19th. My opponents are Keith Lohse and Joseph Galea, and I am excited for the opportunity to discuss the thesis with them 🧑‍🎓
November 20, 2024 at 12:28 PM
Reposted by Christian Magelssen
What are relatively simple things that you wish researchers would report, or would report better, that you have to keep pointing out in reviews?
May 5, 2024 at 6:16 PM
New preprint out: www.biorxiv.org/content/10.1.... We tested whether
skilled and elite slalom racers benefit from reinforcement learning over instruction-based coaching. Our evidence supports reinforcement learning as an effective teaching
method #skilllearning #motorlearning #alpineskiing (1/n)
Reinforcement learning enhances training and performance in skilled alpine skiers compared to traditional coaching instruction
Skilled performers need skillful and adaptive movement strategies to solve tasks effectively. Typically, performers learn these strategies with instruction-based teaching methods where coaches offer performers a correct solution. Inspired by recent evidence from decision neuroscience, we asked whether skilled performers learn strategy choices better with an evaluation-based training strategy (reinforcement learning). To address this question, we conducted a three-day learning experiment with skilled alpine ski racers (n=98) designed to improve their performance on flat slopes on slaloms with four strategies at their disposal to achieve this goal. We compared performance and strategy choices of three groups: a reinforcement learning group, that only received feedback about their race times after every run, a supervised (free choice) learning group, that received strategy instructions from their coach, and a supervised (target skill) learning group, being coached to use the theoretically optimal strategy for skiing well on flats. We found that despite making similar strategy choices, the skiers in the reinforcement learning group, showed greater improvements in their race times during the training sessions than their counterparts in the supervised (free choice) learning group and outperformed them during a subsequent retention test. Surprisingly, the skiers in the reinforcement learning group even showed descriptively (but not significantly) better performance than those in the supervised (target skill) learning group. Our findings show that reinforcement learning can be an effective training strategy for improving strategy choices and performance among skilled performers, even among the best ones. ### Competing Interest Statement The authors have declared no competing interest.
www.biorxiv.org
April 30, 2024 at 9:38 AM
Reposted by Christian Magelssen
OMG, this is going to be awful! A lot of REALLY bad science is going to come out of this. #stats
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March 29, 2024 at 4:02 AM
Reposted by Christian Magelssen
Accurate movements are essential, determining whether a drink is filled or spilled, or whether a rock climber summits or plummets.

Where do motor errors/biases in reaching originate? Read our paper to find out!

Feedback always welcomed.

www.biorxiv.org/content/10.1...
March 22, 2024 at 7:23 AM
Reposted by Christian Magelssen
Interested in replication research? Consider writing a commentary for the next special issue in Meta-Psychology which will publish critiques of the article "Replication value as a function of citation impact and sample size": open.lnu.se/index.php/me...
March 18, 2024 at 11:22 AM
Reposted by Christian Magelssen
I am getting tired of people who criticize frequentist statistics, but then equate frequentist statistics with null hypothesis significance testing. Often leads people to say silly things such as 'p-values only allow you to reject H0, not accept it' - completely ignoring equivalence testing.
March 16, 2024 at 2:36 PM