What it is
12.85M Duolingo vocabulary sessions from 115k learners, structured into forgetting curves, word difficulty tables, and recall stats across 6 languages. ~12.85M vocabulary practice sessions from 115,222 Duolingo learners across 6 languages, structured as analysis-ready forgetting curves, per-word difficulty tables, and course-level recall statistics.
Key results
- 12,854,226 vocabulary practice sessions
- 115,222 Duolingo learners across 6 languages
- Derived from a 379 MB raw trace over a 13-day 2013 window
Useful for modeling recall decay and estimating item difficulty in spaced-repetition systems.