NOTE ON METHOD 145

bious in this and in other ways. Valuable developments in ques-
tionnaire construction post-dated many of the studies reported
here.

3. Not only are the samples different, but the dates at which
the studies were made vary from the early 1930s to the 1940s.
Since both these factors vary, it is impossible to know whether
to attribute differences in results to differences in the samples of
people studied (including the locale of the study), or to differ-
ences in the dates at which the studies were made, or to both.
Thus, differences between Ellsworth, Chicago, 1937, and Link and
Hopf, 1946, may reflect differences between an industrial section
in a metropolis and a group of towns larger than 2,500, or differ-
ences in the dates at which the studies were made, or neither, or
both. No two studies are so similar in other respects that they
provide a reliable trend of popular reading in this sense.

4. Many categories used in the studies are not standardized, so
that it is difficult to match them with one another. On such a
simple matter as age, for example, results aljg,,reported in almost
as many classifications as there are stydies. One survey classifies
age into the groups 20-34, 35-54, 55, and over; another, in 21-39,
40, and over; and another, into 20-29, 30—44, 45, and over. Any
generalization on the relationship of age to public library use
must be based upon rough equations of such categories. Again,
the terms “children” and “adults” are variously defined in the
studies. Such difficulty is met at various points, and not only in
describing personal characteristics. Thus, the different definitions
of “library users” in various studies make generalization hazard-
ous.

5. The studies originally had various purposes, and hence are
formulated and reported in diverse ways. In several cases data
which might have been of value to us were simply not presented
in usable form, and no amount of adaptation could reformulate
them properly. Analysis of the data is deficient in several cases.

6. Finally, too many of the studies fail to explain their pro-
cedures. The careful reader cannot evaluate the methodology in
some cases, simply because it is not adequately described; this
necessitates general caution in using the results. For example,