The mediating effect of context variation in mixed practice for transfer of basic science.

Applying a previously learned concept to a novel problem is an important but difficult process called transfer. Practicing multiple concepts together (mixed practice mode) has been shown superior to practicing concepts separately (blocked practice mode) for transfer. This study examined the effect of single and multiple practice contexts for both mixed and blocked practice modalities on transfer performance. We looked at performance on near transfer (familiar contexts) cases and far transfer (unfamiliar contexts) cases. First year psychology students (n = 42) learned three physiological concepts in a 2 × 2 factorial study (one or two practice contexts and blocked or mixed practice). Each concept was practiced with two clinical cases; practice context was defined as the number of organ systems used (one system per concept vs. two systems). In blocked practice, two practice cases followed each concept; in mixed practice, students learned all concepts before seeing six practice cases. Transfer testing consisted of correctly classifying and explaining 15 clinical cases involving near and far transfer. The outcome was ratings of quality of explanations on a 0-3 scale. The repeated measures analysis showed a significant near versus far by organ system interaction [F(1,38) = 3.4, p < 0.002] with practice with a single context showing lower far transfer scores than near transfer [0.58 (0.37)-0.83 (0.37)] compared to the two contexts which had similar far and near transfer scores [1.19 (0.50)-1.01 (0.38)]. Practicing with two organ contexts had a significant benefit for far transfer regardless of mixed or blocked practice; the single context mixed practice group had the lowest far transfer performance; this was a large effect size (Cohen's d = 0.81). Using only one practice context during practice significantly lowers performance even with the usually superior mixed practice mode. Novices should be exposed to multiple contexts and mixed practice to facilitate transfer.