Cognitive load

Cognitive load theory holds that working memory can process only a limited number of elements at once. The load breaks down into the complexity of the material itself, the load the teaching material adds unnecessarily, and the effort that actually goes into learning. Only the middle category can be designed away.

Material that asks too much at once does not produce half a result but almost none. That explains why a complete, correct and exhaustive module often works worse than a shorter one covering less.

The classic mistake is a screen with an animation running, a voice talking, subtitles scrolling and text on screen, four channels fighting for the same attention. For operators, the real environment comes on top of that: noise, time pressure, gloves. Anyone making material for use on the floor has to assume less attention is available, not more.