DDC and Purchased Cataloging

As in the previous technical services courses, knowing how to do the various tasks needed to create a complete cataloging record does not mean that catalogers should ignore the many options available now for purchasing or copying cataloging. Many of these options provide a Dewey Decimal Classification number that has already been determined by either the Library of Congress or some other institution doing the cataloging. If the cataloging seems to be professionally done, there is no reason to doubt the quality of the DDC notation assigned, but as with the other areas covered, double-checking all information should be an automatic part of the cataloging process.

Shortening DDC numbers

One thing that has been an ongoing problem with DDC numbers is their length. This course has addressed a few of the reasons why the numbers in Dewey become lengthy. Confusion has existed for catalogers who do not understand how numbers are created with DDC. There have been libraries where limits have been set for the number of digits that will be assigned for Dewey numbers, without a clear understanding of how those numbers were developed. Hopefully, it is now clear that there are specific reasons for and that logic does exist in the development of Dewey numbers. If a library wants to limit the number of digits it uses in notations from the DDC, there are also guidelines for this process.

When looking at copied or purchased cataloging, Dewey numbers are usually derived from the unabridged edition of DDC. This often results in longer numbers because of a higher level of specificity in the subjects. Often times in a Dewey number found in purchased cataloging or in MARC (Machine Readable Cataloging) records, there are some marks spaced part way through the Dewey number:

025.3’0973

025.4’31

025.4’9

These spacers (‘) are included to show the cataloger a safe place to split the DDC notation without changing the meaning of the number in relation to other items classified nearby. If a library wished to shorten the examples above, they could become:

025.3

025.4

025.4

This indicator offers libraries that prefer shorter numbers a way to still maintain the integrity of the DDC. It is important not to just cut off numbers at a predetermined number of digits. If a number needs to be shortened, it is preferable to use the spacing indicators provided with purchased cataloging or in MARC records. If this is not available for help, the number should be looked up in the DDC and carefully examined to see if there are elements added (standard subdivision notations, geographic notations, etc.) that could be taken out. These are the only ways a number should be shortened.

In conclusion…

The correct use of the Dewey Decimal Classification System greatly impacts the usability of the library. Patrons rely on the organizational design of the DDC when browsing the library collections and when looking up information in the library catalog. Staff members rely on the DDC when aiding patrons in their search, and when returning the library items to their shelves. The descriptive information in the cataloging record and the subject headings assigned to that cataloging record help the patron determine whether or not a library item is suited to his or her needs. The classification number created through the use of the DDC becomes the key to finding the needed item in the library. The call number created by using all of the elements discussed above gives each library item its own unique address on the library shelves. The catalog gives reference to each address, but a mis-classified or mis-shelved library item in essence becomes lost—unable to be found by the people who might use it. Correct application of the DDC helps to avoid this type of situation, and creates an accessible library for all users.

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