What problem does it solve? Language learners forget vocabulary and grammar without correctly timed reviews, and hand-calculating spaced-repetition schedules is error-prone. This Skill provides the single source of truth for the SM-2 algorithm so every answered review question updates the learner's database with correct intervals, easiness factors, and mastery levels. ## Core Features & Use Cases - Score-to-Quality Mapping: Converts 0-10 review scores into the SM-2 0-5 quality scale using a fixed floor rule. - Interval and Easiness Updates: Applies the official SM-2 formulas for interval growth, easiness-factor adjustment (floored at 1.3), and repetition resets on wrong answers. - Mastery and Queue Routing: Tracks consecutive correct/incorrect streaks to adjust mastery levels and routes items into today, tomorrow, this_week, or later review queues. - Use Case: After a learner answers a vocabulary question and scores 8/10, the tutor maps it to quality 4, computes the next due date, updates spaced-repetition.json via the update-db.py script, and places the item in the correct review queue. ## Quick Start Ask the tutor to grade my review answer for item vocab_huis with a score of 8 and schedule its next review using the SM-2 rules.
