We have about nearly a century of experimental psychology, both before pre- and post-Cognitivism. There are thousands of papers describing various attributes of how people learn. But I feel it’s important to remember that the overwhelming majority of this research studies people learning things they don’t actually care about—either synthetic material in a lab setting or students in a school classroom.
So when we read reports that, for example, people often have trouble Transfer learning generalizing worked examples to similar problems, that’s probably at least partially true… but it’s probably at least in part because they weren’t actually paying as much attention to the material as they would be if they actually cared.
Head-to-head relative effects, like the Spacing effect and Generation effect, are probably safer from this objection than absolute measures, like Pressley, M., Ghatala, E. S., Woloshyn, V., & Pirie, J. (1990). Sometimes Adults Miss the Main Ideas and Do Not Realize It: Confidence in Responses to Short-Answer and Multiple-Choice Comprehension Questions. Reading Research Quarterly, 25(3), 232. But I’d expect the magnitude of relative effects often to attenuate when intrinsic interest is greater.
This is the general case of Most (especially early) experimental literature on the spacing effect involves inauthentic learning environments.
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