Video tutorials
Narrated walkthroughs of Open Lab and of building tasks in the lab.js builder. Each has subtitles in 12 languages, chapters and a transcript, the files to follow along directly under the player, and a link to its docs page.
Files for this video
- ↓ one-trial.jsonThe builder file this video starts from (the end of the previous video).
- ↓ loop.jsonThe builder file at the end of this video. The next video starts from it.
The lab.js builder: a reaction-time task, step by step
Many trials with a Loop
3:19 · narrated, with subtitles in 12 languages · recorded in October 2026
The trial from the previous video, repeated forty times: a loop with a table of trial types, sampling without replacement, the circle's colour taken from the loop, and the data that shows it.