“Desirable difficulties” (bjork) suggests that introducing difficulties in learning will benefit long term #learning. The empirical literature indicates that desirable difficulty effects may not work in conditions where working #memory is already stressed.
In the paper “Undesirable Difficulty Effects in the Learning of High-Element Interactivity Materials” John Sweller et al discusses theoretical and empirical work in the context of cognitive load theory to argue that the effectiveness of desirable difficulties in learning may be moderated by the working memory load imposed by the instructional material.
The review looked at three types of desirable difficulty effects: testing, generation, and varied conditions of practice.
The findings indicates that desirable difficulty effects are not always obtained and that cognitive load theory may be used to explain many of these contradictory results.
Many failures to obtain desirable difficulty effects may occur under conditions where working memory is already stressed due to the use of high element interactivity information. Under such conditions, the introduction of additional difficulties may be undesirable rather than desirable.