Proactive Inhibition; A Function of Time-Interval

The concurrent effects of proactive and retroactive inhibition.

“…When considered together, these two experiments reveal that the time interval chosen in the present study, 48-hr., maximizes the possible influence of PI on recall. Moreover, other evidence (Melton & Von Lackum, 1941;Ray, 1945) indicates the maximal effect of PI on transfer to be between 24-48 hr., which tends to justify the 24-hr. PI-OL interval used.…”

Retroactive and proactive inhibition of verbal learning.

“…We have been unable to find such an experiment in the literature within this period. Ray (1945) studied List 2 acquisition as a function of the interval since the learning of List 1. Although he speaks of PI, the design is appropriate only to conclusions about negative transfer.…”

The measurement of transfer of training.

“…In such cases, percent improvement is found by dividing the amount of improvement by the initial score made by the control group. This method of expressing transfer has been referred to in the present paper as Formula [1], If the experiment has included a foretest as well as an after-test, the improvement of both the control group and the transfer group may be found by subtracting each group's initial score from its final score (7,12,22,23,37,43,69,88,97,117,130,131). Percent improvement due to transfer may then be obtained by substituting the appropriate values in Formula [la].…”

“…Several studies, however, have been concerned with indicating per cent inhibition. In the studies of Melton and Von Lackum (85) and of Ray (97), the per cent of inhibition is found by dividing the difference in scores of the control and transfer groups by the control group score. It is evident that a simple reversal of signs has been made in this case, since a positive inhibition means a negative transfer.…”

“…[2], and [2a] to express improvement resulting from transfer report the measurement of the performance scores on both the initial and final tasks during only the initial stages of the learning, often by means of a "test" which samples the performance on the first trial or on the first few trials (3,5,7,12,22,23,32,33,37,40,65,69,89,97,101,130). In other studies, the values used represent the learning scores of both control group and experimental group, having been derived from a measurement of learning carried well beyond the initial stage.…”