ABSTRACT
Given the option of practicing one type of activity over and over or practicing a random mix of related activities, the latter results in superior learning in most contexts. For example, students learn more effectively when solving a mix of related problems versus solving blocks of just one kind of problem. It is worth noting that even when the aforementioned conditions are satisfied, students overwhelmingly perceive that they learn more effectively with blocked versus interleaved practice. Blocked practice allows students to get into a mode of thoughtless repetition, applying the same problem-solving strategy over and over. Interleaving avoids this, requiring students to continuously discriminate problem types and then consciously select the appropriate problem-solving strategy. This specific type of extra mental effort—problem discrimination and strategy selection—seems to be the key to interleaving.
