In an experiment, prior to processing instructional explanations N = 75 students received either (a) contrasting cases plus comparison prompts, (b) contrasting cases plus provided comparisons (i.e., model answers to the comparison prompts), or (c) no preparation intervention. We found that the learners with preparation intervention learned more and with a higher degree of efficiency, perceived less extraneous load, and experienced a higher feeling of smooth automatic running while they processed the explanations than the learners without a preparation intervention. These findings suggest that comparing contrasting cases serves a focusing function. Furthermore, we found that the learners in the provided comparisons condition acquired more conceptual knowledge from the explanations than the learners in the prompted comparisons condition. This result indicates that providing high amounts of instructional guidance while learners compare contrasting cases can have an added value in comparison to providing comparison prompts concerning the resulting preparation for future learning.