Interleaved vs. Blocked Practice: The Contextual Interference Effect (2D)

Educational psychology has a well-documented paradox: the practice schedule that feels most productive is often not the one that produces the strongest long-term learning. This 2D simulator runs three skills through either a blocked schedule (all reps of skill A, then all of B, then all of C) or an interleaved schedule (skills cycled A-B-C-A-B-C…), plotting a scrolling trial-sequence strip plus two live charts: immediate in-practice accuracy per trial, and a full retention-vs-delay curve computed from a short-term strength model and a discrimination index that accumulates every time the schedule switches between skills — the mechanism believed to drive the contextual-interference effect. Move the retention-delay slider forward in simulated days and watch predicted recall diverge: blocked practice looks better right after training, but interleaved practice decays more slowly and overtakes it, mirroring findings from real classroom and motor-skill studies on desirable difficulties in learning.