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Navigating the Tyndale Stacks: Home

Dewey Decimal System Overview

The Dewey Decimal System (DDS) divides the world’s books into ten major categories called classes (which are represented by a digit in the hundreds-place). Each class is then divided into ten subclasses (represented by the tens-place), which are themselves divided into another ten (represented by the ones-place). So the 800s are the Literature class, the 820s are English Literature, and the 822s are English Drama (see Fig. 1 for all major class and subclass divisions within the DDS).

To achieve an even greater level of specificity, class numbers are often followed by a number after a decimal point. So 822.1 is Early English Drama, while 822.2 is Pre-Elizabethan Drama, and 822.3 is Elizabethan Drama. (In case you were wondering, Shakespeare has his own "Dewey number": 822.33.)

Book Labeling

To achieve the maximal level of specificity, a book’s Dewey number is followed by some variation of the author/major editor's last name. Different libraries have different ways of expressing this information. There are three major methods:

  1. Include the author/editor's entire last name
  2. Include only the first three letters of their name
  3. Include a "cutter number," an alpha-numeric code for a particular author's last name

Unfortunately, since NSA has received so many books from various libraries over the years, all three of these methods for expressing the author/editor's last name are represented in our library. That is, some of our books include the entire last name of the author/editor, some include an abbreviated version of their last name, and some include a cutter number (see Fig. 2). We are currently in the process of relabeling our books so that they are uniformly labeled with the author’s entire last name, but with a collection numbering around 45,000 volumes, this is a long-term project to say the least!

A book's respective Dewey number and the name of its author/editor are printed--along with the book's home location, barcode number, and any volume/copy numbers--on a label affixed to the book's spine. (Labels are occasionally affixed to a book's front cover if the spine is too small.) A book's Dewey number, author/editor last name, and volume/copy number (if applicable) are collectively referred to as the book's "call number" (see Fig. 3).

Fig. 3

Fig. 1

Fig. 2

Shelf Reading

Books are arranged numerically (according to Dewey number) and alphabetically (according to author/editor last name) from left to right and from top to bottom on the shelves. For example, a book with the call number "230.1 Tracy" would be located on the shelves after a book with the call number "230.1 Ralston," but before a book with the call number "230.11 Augustine." This is because "Ralston" is alphabetically prior to "Tracy," while "230.1" is numerically prior to "230.11."

A stack of shelves thus arranged is called a "standard." To navigate a standard, begin on the left side of the topmost shelf (represented by shelf 1 in Fig. 4) and then scan left-to-right and top-to-bottom until you reach the end. Once you’ve reached the end of one standard, begin again on the left side of the topmost shelf of the next standard (represented by shelf 8), which will be located to the right of the standard you just completed. Once you’ve reached the end of a whole row of standards, find the start of the row which picks up where you left off, and begin again from there. (See Fig. 4 for an illustration of the flow of books through the library stacks.)

Fig. 4