The major finding in this study was the positive effect that CAI had on achievement
of elementary school children. In the typical application, students received
approximately 26 hours of CAI: 15 minutes per day, for 4 days a week, and for
a total of 26 weeks. The effect of this instruction was to raise student achievement scores (relative to conventional instruction) by 0.47 standard deviations, or
from the 50th to the 68th percentile. This effect is similar to effects reported in
earlier reviews. Burns (1981) and Hartley (1978), for example, each reported
gains of approximately 0.4 standard deviations from CAI in elementary school
mathematics. The closeness in results from these different meta-analyses is
impressive in view of the minimal overlap in the studies they covered and the
different methodologies used in the analyses.