AbstractPrevious studies have promoted the use of elaborative interrogation (a “why”‐questioning strategy) for the acquisition of factual information. One assumption in these studies is that prior knowledge influences when students will be able to use the strategy, with greater prior knowledge leading to higher recall performance. In the studies reviewed here, the effect of prior knowledge on strategy effectiveness was investigated. Specifically, students' performances were compared for materials about which they possessed substantial prior knowledge, little prior knowledge, inconsistent prior knowledge, or shared prior knowledge. In general, the data support the use of elaborative interrogation when studying alone or in dyads especially when learners possess some relevant prior knowledge about the new inform