Attempting to retrieve information from memory enhances subsequent learning even if the retrieval attempt is unsuccessful. Recent evidence suggests that this benefit materializes only if subsequent study occurs immediately after the retrieval attempt. Previous studies have prompted retrieval using a cue (e.g., whale–???) that has no intrinsic answer. Experiment 1 replicated prior word pair studies, but in Experiment 2, when participants learned meaningful trivia questions, testing enhanced learning even when subsequent study was delayed. Even in Experiment 3, when subsequent study was delayed by up to 24 hr, tests enhanced learning on a final test another 24 hr later. These findings may give comfort to educators who worry that asking a question or giving a test, on which students inevitably make mistakes, impairs learning if feedback is not immediate. They also suggest that there is a consensus in the literature thus far: Questions with rich semantic content enhance subsequent learning even when feedback is delayed, but less meaningful questions without an intrinsic answer enhance learning only when feedback is immediate.

Retrieving information from memory enhances learning, a finding sometimes referred to as the testing or retrieval effect (Roediger & Butler, 2011; Roediger & Karpicke, 2006). Retrieval attempts are highly beneficial when they are successful (e.g., Karpicke & Roediger, 2008), but this article focuses on the effects of unsuccessful retrieval attempts.

A growing body of evidence suggests that attempting to retrieve information from memory enhances subsequent learning even when the retrieval attempt is unsuccessful (Grimaldi & Karpicke, 2012; Hays, Kornell, & Bjork, 2013; Huelser & Metcalfe, 2012; Izawa, 1970; Knight, Ball, Brewer, DeWitt, & Marsh, 2012; Kornell, Hays, & Bjork, 2009; Richland, Kornell, & Kao, 2009; Vaughn & Rawson, 2012). Most of these studies included a study condition, in which participants were shown a...