Objective: The objective was to conduct meta-analyses that investigated the effects of two training strategies, increasing difficulty (ID) and part-task training (PTT), on transfer of skills and the variables that moderate effectiveness of the strategies.
Background: Cognitive load theory (CLT) provides a basis for predicting that training strategies reducing the intrinsic load of a task during training avail more resources to be devoted to learning. Two strategies that accomplish this goal, by dividing tasks in parts or by simplifying tasks in early training trials, have offered only mixed success.
Method: A pair of complementary effect size measures were used in the meta-analyses conducted on 37 transfer studies employing the two training strategies: (a) a transfer ratio analysis on the ratio of treatment transfer performance to control transfer performance and (b) a Hedges' g analysis on the standardized difference between treatment and control group means.
Results: PTT generally produced negative transfer when the parts were performed concurrently in the whole transfer task but not when the parts were performed in sequence. Variable-priority training of the whole task was a successful technique. ID training was successful when the increases were implemented adaptively but not when increased in fixed steps. Both strategies provided evidence that experienced learners benefited less, or suffered more, from the strategy, consistent with CLT.
Conclusion: PTT can be successful if the integrated parts are varied in the priority they are given to the learner. ID training is successful if the increases are adaptive. The fundamental elements of CLT are confirmed.