Knowledge Taught in School: What Is Remembered?

Popular belief holds that much of what is taught in classrooms is forgotten shortly thereafter. However, there is evidence from numerous studies that long-term retention for knowledge taught in school is substantial. These studies are reviewed, and several variables that affect the ability to remember are discussed. The article concludes that (a) students retain much of the knowledge taught in the classroom; (b) retention decreases over time as a function of the length of the retention interval but the forgetting curves for knowledge taught in school do not decline as rapidly or asymptote as low as the curves observed in traditional laboratory studies; (c) increasing the level of original learning differentially affects retention performance; (d) both instructional content and assessment tasks affect learning and retention, with one of the most consistent effects being that recognition tasks are retained at higher levels than recall tasks; (e) most instructional strategies that promote higher levels of original learning do not result in differentially better retention (however, several exceptions are discussed); and (f) while higher ability students learn and remember more than lower ability students, there is no evidence for differential forgetting. Implications for research and teaching are discussed.