It should be noted that no attempt was made to compare the
content of the gift books with the content of the purchased books. A later analysis separated
the samples into three categories, Social Sciences, Sciences, and Humanities. Table 2 shows
that the content of the two groups of books was very different. This could be perceived as
a weakness to the study. Still, the intent of the study was to compare gifts added to the library
to an equally sized group of purchased books. If content-similar purchased books were
selected, this would have delayed placing the non-gift books into circulation and the gift
books would have been available for circulation for a longer period of time than the non-gift
books. So emphasis was placed on having same-sized groups and an equal period of time for
each group to be used rather than on the content of each group.