The Mix-Up Regarding Mixed and Unmixed Lists in Spacing-Effect Research

• Published in: Journal of experimental psychology. Learning, memory, and cognition Vol. 25; no. 4; pp. 1071 - 1076
• Main Authors: Toppino, Thomas C, Schneider, Mark A
• Format: Journal Article
• Language: English
• Published: Washington, DC American Psychological Association 01-07-1999
• Subjects: Biological and medical sciences; Experimental Replication; Free Recall; Fundamental and applied biological sciences. Psychology; Human; Learning; Learning. Memory; Memory; Psychology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Serial Position Effect; Theory; Words (Phonetic Units); Human; Free recall; Memory; Strategy; Cognition; Experimental study; Rehearsal
• ISSN: 0278-7393; 1939-1285
• DOI: 10.1037/0278-7393.25.4.1071

J. W. Hall (1992)
proposed that participants in spacing-effect experiments use massed
repetitions as an opportunity to study previously presented items.
He provided apparent evidence for this displaced-rehearsal strategy
in a free-recall experiment involving unmixed lists consisting of
all massed or all spaced repetitions. He argued that this strategy
produces artifactual spacing effects when experiments involve mixed
lists containing both massed and spaced repetitions. This raises the
specter that much of the spaced-repetition literature might be
contaminated by artifactual results because most experiments have
used mixed-list designs. The authors replicated Hall's experiment
and extended it by including critical control conditions. Although
Hall's results are replicable, they are primarily attributable to
factors that were uncontrolled in his study. There seems to be no
compelling reason to question spacing effects obtained with
mixed-list designs.