b'Determining the Subject of the WorkThe first and most important step in subject cataloging is to ascertain the true subject of the materialbeing cataloged. This concept of aboutness should never be far from a subject catalogersthoughts. It is a serious mistake to think of subject analysis as a matter of sorting through materialand fitting it into the available categories, like sorting the mail, rather than focusing first on thematerial and determining what it is really about.Many times the subject of a work is readily determined. Hummingbirds is obviously the subject ofa book entitled The Complete Book of Hummingbirds. In other cases the subject is not so easy todiscern, because it may be a complex one or the author may not express it in a manner clear tosomeone unfamiliar with the subject. The subject of a work cannot always be determined from thetitle alone, which is often uninformative or misleading, and undue dependence on it can result inerror. A book entitled Great Masters in Art immediately suggests the subject Artists, but closerexamination may reveal the book to be only about painters, not about artists in general. Afterreading the title page, the cataloger should examine the table of contents and skim the preface andintroduction, and then, if the subject is still not clear, examine the text carefully and read parts of it,if necessary. In the case of nonbook materials, the cataloger should examine the container, the label,any accompanying guides, etc., and view or listen to the contents if possible. Only after thispreliminary examination has been made is it possible to determine the subject of a work. If themeaning of technical terminology is not clearly understood, reference sources should be consulted.Only when the cataloger has determined the subject content of a work and identified it with explicitwords can the Sears List be used to advantage. The List is consulted to determine one of threepossibilities. If the word the cataloger chose to describe the subject content of the work is anestablished heading in the List, then that heading should be assigned to the work.If the word the cataloger chose is a synonym or alternate form of an established heading in the List,then the cataloger forgoes the word that first came to mind in favor of the term from the List. A thirdpossibility is that there is no heading in the List for the subject of the work at hand, in which casethe cataloger must formulate the appropriate heading, add it to the librarys subject authority filewith its attendant references, and then assign it to the work.Many books are about more than one subject. In that case a second or third subject heading isnecessary. Theoretically there is no limit to the number of subject entries that could be made for onework, but in practice an excess of entries is a disservice to the user of the catalog. More than threesubject headings should be assigned to a single item only after careful consideration. The need formore than three may be due to the catalogers inability to identify precisely the single broaderheading that would cover all the topics in the work. Similarly, a subject heading should not beassigned for a topic that comprises less than one third of a work. The commonest practice, known asthe Rule of Three, may be stated as follows: As many as three specific subject headings in a givenarea may be assigned to a work, but if the work treats of more than three subjects, then a broaderheading is used instead and the specific headings are omitted. A work about snakes and lizards, forA-19'