Josh de Leeuw
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joshdeleeuw.bsky.social
Josh de Leeuw
@joshdeleeuw.bsky.social
Cognitive Scientist at Vassar College. Currently working on open source tools for researchers.

Creator and maintainer: https://www.jspsych.org
Today from 5-6 ET / 2-3 PT, Becky Gilbert is going to host an open office hour for help with jsPsych. Becky is a software engineer for Children Helping Science. Did you know that you can now use jsPsych to build studies that run on CHS (formerly Lookit)?
We've just
launched a Discord server for #jsPsych users to collaborate and get technical help.

I'll be hosting office hours tomorrow from 10:30-11:30 AM EDT. Hop in with any questions!

discord.gg/RCKWJ4qb3p
Join the jsPsych Developers Discord Server!
Check out the jsPsych Developers community on Discord - hang out with 17 other members and enjoy free voice and text chat.
discord.gg
October 21, 2025 at 3:30 PM
Really enjoyed getting to participate in open source development with the team from COS! Pretty soon, you'll be able to connect an OSF component to DataPipe (pipe.jspsych.org) directly through your OSF account.
October 16, 2025 at 3:56 PM
doing live office hours in 10 minutes! drop by with any jspsych questions and I'll do my best to assist.
We've just
launched a Discord server for #jsPsych users to collaborate and get technical help.

I'll be hosting office hours tomorrow from 10:30-11:30 AM EDT. Hop in with any questions!

discord.gg/RCKWJ4qb3p
Join the jsPsych Developers Discord Server!
Check out the jsPsych Developers community on Discord - hang out with 17 other members and enjoy free voice and text chat.
discord.gg
October 14, 2025 at 2:21 PM
We've just
launched a Discord server for #jsPsych users to collaborate and get technical help.

I'll be hosting office hours tomorrow from 10:30-11:30 AM EDT. Hop in with any questions!

discord.gg/RCKWJ4qb3p
Join the jsPsych Developers Discord Server!
Check out the jsPsych Developers community on Discord - hang out with 17 other members and enjoy free voice and text chat.
discord.gg
October 13, 2025 at 1:46 PM
Application review begins on 10/1; still time to apply!
September 19, 2025 at 6:23 PM
Reposted by Josh de Leeuw
We are running a virtual hackathon for #hacktober! Info and signup here: jspsych.github.io/hackathon/virtual_2025.html

We will be hosting drop in office hours help during the hackathon, so this is a great chance to level up your jspsych skills!
jsPsych Hackathons
jspsych.github.io
September 16, 2025 at 5:42 PM
Reposted by Josh de Leeuw
Don't worry academics, it's still only August 32nd. Still plenty of time!
September 1, 2025 at 9:31 AM
Reposted by Josh de Leeuw
tryin' to be in the band, not the band manager. todd.gureckislab.org/2024/09/25/l...
August 6, 2025 at 2:57 PM
Representing @vassar.bsky.social at #cogsci2025. My favorite part of the conference was catching up with all these amazing alums!
August 3, 2025 at 1:51 AM
Vassar College is hiring a tenure track assistant professor in cognitive science. vassar.wd1.myworkdayjobs.com/en-US/Vassar...

I'll be at #CogSci2025 - happy to chat about the position and life at Vassar.
Assistant Professor of Cognitive Science, Tenure Track
Department Cognitive Science Vassar College is dedicated to providing equal employment opportunities to all applicants and employees and welcomes applications from individuals of all backgrounds. Deci...
vassar.wd1.myworkdayjobs.com
July 29, 2025 at 1:56 PM
Heading to #CogSci2025 🥳
July 29, 2025 at 10:50 AM
July 14, 2025 at 6:54 PM
Want to know what kinds of studies webcam-based eye tracking can be used for? Here's our take on the current tech. This certainly isn't the first paper on this topic, but it provides some converging evidence about the viability of eye tracking with online methods. online.ucpress.edu/collabra/art...
What Paradigms Can Webcam Eye-Tracking Be Used For? Attempted Replications of Five Cognitive Science Experiments
Web-based data collection allows researchers to recruit large and diverse samples with fewer resources than lab-based studies require. Recent innovations have expanded the set of methodolgies that are...
online.ucpress.edu
July 8, 2025 at 7:57 PM
Reposted by Josh de Leeuw
If you could change 1 or 2 things about the software used for academic journal editorial processes (e.g., manuscript submission, peer review, publishing), what would it be? 👀

#academicsky
June 24, 2025 at 1:26 AM
If you could change 1 or 2 things about the software used for academic journal editorial processes (e.g., manuscript submission, peer review, publishing), what would it be? 👀

#academicsky
June 24, 2025 at 1:26 AM
Reposted by Josh de Leeuw
After a few days to fix some bugs, we will be holding another online Psych-DS tutorial on Wednesday, June 4, 12pm EDT.

This is an informal workshop designed to help you convert a dataset to Psych-DS - BYO or find an open dataset at osf.io/mbvk4.

Sign up here:
docs.google.com/forms/d/e/1F...
May 29, 2025 at 6:18 PM
Reposted by Josh de Leeuw
That's a wrap on our first ever hackathon! Thanks to all of the wonderful people who attended. Lots of amazing projects and collaborations got started. 🥳
May 15, 2025 at 8:15 PM
I feel this too, but I think it might be a context effect. My working memory in this context is just not very good compared to working with LLMs.
The more I use LLMs for academic work, the punier my working memory feels.
May 14, 2025 at 12:39 AM
I made a page that lets you see hyperbolic teal - which could be olo.

jodeleeuw.github.io/olo/
April 21, 2025 at 1:57 PM
jspsych will soon* support generating psych-ds metadata automatically from an experiment timeline. we have done most of the implementation and are ironing out the final details.

*probably summer 2025
Psych-DS is (1) spellcheck for your datasets and (2) a pathway to standardizing data in our academic fields that *everyone* can learn.

And it's live RIGHT NOW!

psych-ds.github.io

(This is the announcement post I've been leading up to)
Psych-DS
A specification for psychological datasets. JSON metadata, predictable directory structure, and machine-readable specifications for tabular datasets.
psych-ds.github.io
April 9, 2025 at 11:59 PM
Reposted by Josh de Leeuw
Psych-DS is (1) spellcheck for your datasets and (2) a pathway to standardizing data in our academic fields that *everyone* can learn.

And it's live RIGHT NOW!

psych-ds.github.io

(This is the announcement post I've been leading up to)
Psych-DS
A specification for psychological datasets. JSON metadata, predictable directory structure, and machine-readable specifications for tabular datasets.
psych-ds.github.io
April 9, 2025 at 7:37 PM
Reposted by Josh de Leeuw
Today's post is on @mcxfrank.bsky.social's book Experimentology, and specifically the chapter on Project Management

experimentology.io/013-manageme...

(full disclosure, I've collaborated on projects with Mike, specifically on ManyBabies, which gets a shout-out in this chapter)
April 4, 2025 at 4:04 PM
Reposted by Josh de Leeuw
I have a big update* coming next week for anyone that works with research data, especially in the social sciences.

To warm up, I'm recapping resources that help you develop good intuitions for data management - if you have others you'd like to see, share below!

(*It's about Psych-DS, get excited!)
April 2, 2025 at 8:04 PM
Reposted by Josh de Leeuw
🌍 Join the Heat & Cognition ManyLabs project! We're studying how extreme heat affects human thinking, social behavior & well-being — globally.
Contribute & co-author:
🔗 Info: heatandmind.wordpress.com
📋 Sign up: www.soscisurvey.de/HeatandCogni...
#ManyLabs #EnvironmentalPsychology
The Heat and Cognition Project: The Collective Cost of Extreme Heat
heatandmind.wordpress.com
March 27, 2025 at 3:36 PM
We still have space for a few more folks to attend. All expenses paid!
We're hosting a hackathon in May! This is aimed at jsPsych users who want to learn how to contribute to open source software and extend jsPsych. It's free, and we'll cover travel expenses. Learn more and sign up here:

jspsych.github.io/hackathon/sp...
jsPsych Spring 2025
jspsych.github.io
March 26, 2025 at 1:37 PM