recalled is in proportion to the number of its associations.

The third factor upon which goodness in memory depends is the
organization of associates. Number of connections is an aid to
memory--but systematization among these connections is an added help.
Logical arrangement of facts in memory, classification according to
various principles, orderly grouping of things that belong together,
make the operation of memory more efficient and economical. The
difference between mere number of associations and orderly arrangement
of those associations may be illustrated by the difference in efficiency
between the housekeeper who starts more or less blindly to look all over
the house for a lost article, and the one who at least knows that it
must be in a certain room and probably in a certain bureau drawer.
Although memory as a whole cannot be improved because of the limiting
power of native retentiveness, memory for any fact or in any definite
field may be improved by emphasizing these two factors: number of
associations and organization among associations.

Although all three factors are operative in securing the best type of
memory, still the efficiency of a given memory may be due more to the
unusual power of one of them than to the combined effect of the three.
It is this difference in the functioning of these three factors which is
primarily responsible for certain types of memory which will be
discussed later. It must also be borne in mind that the power of these
factors to operate in determining recall varies somewhat with age.
Little children and old people are more dependent upon mere
retentiveness than upon either of the others, the former because of lack
of experience and lack of habits of thought, the latter because of the
loss of both of these factors. The adult depends more on the
organization of his material, while in the years between the number of