Interleaved vs. Blocked Practice: The Contextual Interference Effect

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 simulator lets you run 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…), watching each trial land as a block in a growing 3D tower. A short-term strength model tracks immediate practice accuracy per skill, while a separate discrimination index 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 usually looks better right after training, but interleaved practice decays more slowly and can overtake it, mirroring findings from real classroom and motor-skill studies on desirable difficulties in learning.