JL DOCUMENTATION OF LITERATURE COMMISSION VI
ments Office.* The original document catalogue cards are
typewritten and have dimensions of 5 x 8 inches, When pub-
lished by photolithography, these cards are reduced in size to
3 x 5 inches.
As illustrated by Figure 2, the reverse side of & docu-
ment catalogue card may sometimes display a microfilm repro-
duction of the original document.
Document catalogue cards pertaining to photogrammetry
and the related fields of interest are generally not available
from either governmental or commercial sources, This condi-
tion is in contrast with such technical fields as Medicine,
Chemistry, and Biology where commercial organizations publish
document catalogue cards for all published literature in
these fields. In this connection it must be noted that most
agencies of the United States Government which publish ab-
stracts of technical literature are not permitted to concern
themselves with commercial literature of any sort.
D, DOCUMENT CLASSIFICATION
The classifying and filing of document catalogue cards
requires the use of a classification system that possesses
the following desirable gualitiess
a. Simplicity of use. (The practical value of a file of
document catalogue cards depends in part upon the user's
ability to maintain it in an up-to-date condition.)
b. Orderly arrangement. (The titles and sub-titles should
bring together in an orderly arrangement copies of all
catalogue cards concerned with any given concept or group |
of related concepts that may be of interest.) |
c. Universal application. (The system should provide logi-
cally arranged cross references for every type of human
X The Navy Research Section and the Central Air Documents Of-
fice have been recently combined to form the Armed Forces
Technical Information Agency. The document catalogue cards
published by these organizations are available to the vari-
ous agencies of the United States Government. Unfortunate-
ly, however, neither of these organizations makes any pro-
vision for abstracting the articles that have been publish-
ed in "Photogrammetric Engineering", Neither do they pub-
lish abstracts of technical articles regarding photograme
metry, surveying and the graphic arts.
