How complex should tasks be for test-enhanced learning?

If one plans to exploit the Testing effect for Test-enhanced learning (e.g. in a Spaced repetition memory system), should you test yourself on lots of simple items or higher-level tasks, to promote Transfer learning?

Commonplace practice typically advises the former (Spaced repetition memory prompts should usually focus on one atomic unit), but the balance of research is more ambivalent:

There’s also van Gog, T., & Sweller, J. (2015). Not New, but Nearly Forgotten: The Testing Effect Decreases or even Disappears as the Complexity of Learning Materials Increases. Educational Psychology Review, 27(2), 247–264, which claims that the testing effect doesn’t apply to complex tasks, but this seems to be at best only sometimes true.

See also: Retrieval practice and transfer learning

Last updated 2023-09-15.