Published April 7, 2026 · AI in Education
Research consistently shows that learners forget 70-80% of new vocabulary within 24 hours without systematic review. The Ebbinghaus forgetting curve demonstrates that spaced, repeated exposure is the only reliable method for long-term retention. Yet most ESL teachers rely on ad-hoc review methods.
The problem isn't motivation. It's infrastructure. Teachers lack tools that automatically schedule reviews at optimal intervals and track mastery per card.
The SM-2 algorithm calculates optimal review intervals based on: Easiness Factor (per-card difficulty, starting at 2.5), Interval (days until next review, growing exponentially), and Repetition Count. Cards rated ≥3 advance; cards rated <3 reset to day 1.
After generating an AI worksheet, vocabulary can be extracted into a flashcard set automatically. Each card inherits the English term, translation or definition, CEFR level, source worksheet reference, and example sentence.
True vocabulary mastery requires recognition in both directions. Bidirectional flashcard sets track progress separately for each direction with independent SM-2 calculations.
Students access flashcard sets through the Student Hub portal without needing a teacher account. Teachers see aggregated progress data — which students are reviewing regularly and which cards are problematic.
10-20 new cards per day is optimal. More important than new cards is completing all due reviews.
For A1-B1: L1 translation. For B2+: English definitions. The best approach combines both.
Try Edooqoo Free — AI Flashcards with Spaced Repetition
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