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Retention and Obliviscence as a Function of the Time
75
C
L WL Δ Q
1424 1004 420 31.4
1307 1102 205 16.4
1351 893 458 36.2
1245 1090 155 13.4
1258 895 363 31.0
1155 1070 85 7.9
1219 800 419 36.9
1278 1110 168 14.1
1120 1051 69 6.7
1250 1055 195 16.7
m1261 1007 254 21.1
P.E.m=2.7
The average of 45 savings of work expressed in per cents=21.1 (P.E.m=0.8).

A hasty glance at the figures above reveals the fact that for each interval of time the savings in work which become evident when the series is relearned have very fluctuating values. (This saving in work is each time the measure for the amount remembered at the end of the interval.) This is especially the case with their absolute values (Δ), but is also the case with the relative values (Q). The results are taken from the earlier period and suffer from several disturbing influences to which my attention was first drawn by the tests themselves.

In spite of all irregularities in detail, however, they group themselves as a whole with satisfactory certainty into an harmonious picture. As a proof of this the absolute amount of the saving in work is of less value. The latter evidently depends upon the time of day—i.e., upon the changes in the time of the first learning dependent upon it. When this change is greatest (time C), Δ also is greatest; for the time B, they are in ¾ of the cases larger than for the time A (after multiplying by 4/3). On the other hand, the values (Q) found for the relation of each saving of work to the time originally spent, are apparently almost independent of this ratio. Their averages are close together for all three times of day, and do not show any character of increase or decrease in the later hours. Accordingly I here tabulate the latter.