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
- ↓ parameters.jsonThe builder file this video starts from (the end of the previous video).
- ↓ conditions.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
One task, two conditions
2:53 · narrated, with subtitles in 12 languages · recorded in November 2026
Two versions of the instructions in one file: two parameters hold the sentences, and the group code that Open Lab gives each participant chooses between them. A temporary row tests both conditions in the builder's preview.
Up nextFrom the builder to Open Lab2:44 →