3 experiments varying the interval between 2 presentations of paired associates were reported. Other pairs filled the spacing and retention intervals. Pairs consisting of a word and a number as well as pairs consisting of 2 words showed a superiority at 8 sec. and longer retention intervals when presentations were spaced. Increasing the spacing interval beyond 8 sec. did not increase recall, when a 2-sec. rate of presentation was used. A 2-factor explanation of the findings was suggested, in which cue learning was the major factor influencing recall at longer retention intervals, while a 2nd factor was confounded with cue learning at short retention intervals.