Whole and Pabt LEAHiiriNG

One of the practical questions that arise when we
have something to commit to memory is whether the



114 GENERAL PSYCHOLOGY

material should be rehearsed from beginning to end,
or broken up into parts so that each part can be
learned separately and the parts later combined. If
the law represented by Figure 23 held for short
series as well as for long, it would take approxi-
mately twice the time to leam any series as to learn
a series half that length. Part learning would then
evidently be wasteful, because it would take the same
time to leam by parts as to learn by wholes, and
after the parts were learned the order of the parts
would have to be learned also. The law (Figure 23)
holds, however, only for lengths somewhat greater
than the memory span. This memory span is the
amount that can be accurately reproduced after a
single reading. Because very small parts are mem-
orized with relatively greater ease than large parts,
we have no way of determining in advance of expe-
riment whether the easy learning of small parts
compensates for the necessity of linking these parts
together after each has been committed to memory.
Ebbinghaus has shown that when two series of
different lengths are memorized to the point of one
perfect reproduction, the longer series is better re-
tained after 24 hours than is the shorter series.
