Some measurements of the effects of reviews.

The Effect of Study Strategies on the Retention of College Text Material

“…*Dr. Crewe is on the faculty of the University of Minnesota, Minneapolis. Kloess (1935), Stroud and Johnson (1942), and Ausubel and Youssef (1965), also support that conclusion, but lack of time control contaminates their results. With respect to the second problem, the study by Peterson, et ah, indicates that the length of time between review and examination does not affect retention.…”

Time as a Factor in the Retention of College Text Material

“…These results contradicted findings by Ausubel andYoussef (1965), andPeterson, Ellis, ToohiÜ, andKloess (1935). Crewe offered the explanation that in the above studies there was no control for the total time studied (a factor which he did control), therefore, students in the review groups had more time to study and should have earned better retention scores.…”

Spacing effects and their implications for theory and practice

“…For example, English et al (1934) found that four readings of a text at 3-hr intervals were associated with better learning than four consecutive unspaced readings; however, readings at 3-hr intervals were no better than readings at either 1-or 3-day intervals. Similarly, Lyon (1914), Peterson et al (1935), and Sones and Stroud (1940) reported essentially no differences in retention between groups with rereadingreviews spaced 1 and 7, 1 and 9, and 1 and 17 days after original learning. These findings were later corroborated by Ausubel (1966) and by Gay (1973, Experiment 1).…”