# What does a trailing zero mean in a Dewey decimal catalog?December 20, 2008 2:30 PM   Subscribe

Hey Librarians! Why is there a trailing zero on this Dewey number?

I've asked the available meatspace librarians why Tim Wendel's book The New Face of Baseball is cataloged at 796.3570, and the best they can come up with is that it's some topical designation. (The worst so far was, "Good question, troublemaker, I'm not a cataloger.") OK, so if that's it, which topic does a trailing zero indicate? If that's not it, what's going on here? Is it extraneous? FWIW, there's one other book in this collection with the same catalog number, and I can pull up more in the google.
posted by saguaro to Grab Bag (8 answers total) 3 users marked this as a favorite

The short answer is that the last zero is a significant digit. It is a zero, but it is not null.

posted by QIbHom at 3:25 PM on December 20, 2008

I'm not sure if this is useful, or if it even applies, but here, on the Nippon decimal system:

"It is based on the Dewey Decimal System. The system is based upon using each successive digit to divide into nine divisions with the digit zero used for those not belonging to any of the divisions."

My guess is that it is similar for the Dewey Decimal System, and perhaps there are ten subtopics under 796.357, and "0" indicates one of them. If the catalog number is just 796.357, then the topic is more general than 796.3570. For example, 796.357 might be "Baseball" and 796.3570 might be "Baseball during the 1970s". Just a guess though.

I have no idea what topic it would indicate though, or where to find that out, sorry.
posted by jasminerain at 3:29 PM on December 20, 2008

Do you know the long answer, QIbHom? 'Cause I asked the locals with zero results.
posted by saguaro at 3:30 PM on December 20, 2008

There's no real reason why the classification hierarchy wouldn't go further than 3 decimal digits with Dewey Decimal (no logical reason at least. I only learned the Library of Congress system). The only way you'd be able to find out for certain is to get access to the classification system itself. That might not be that hard as when I worked in a library in college we had the Library of Congress classification system in print so perhaps some libraries carry it themselves. There also appears to be an OCLC portal for it, which suggests that any library with OCLC access can simply let you view the information online.

I am not a librarian. I no longer work at a library. And I never worked with Dewey Decimal. But that's where I'd start looking.
posted by Green With You at 3:36 PM on December 20, 2008

The usual Dewey classification for baseball is 796.357. This record from the Library of Congress shows that the whole number for this specific title can be as long as 796.35708968073. There is a wealth of significant info hidden in that long number, probably related to these assigned subject headings:

Baseball players --Latin America --Biography.
Hispanic American baseball players --Biography.
Baseball players --United States --Biography.
Discrimination in sports --United States --History.

Your local library cut if off at the 0. IANAC, just a reference librarian, so I don't know if that 0 was a mistake (the Toronto Public library cut it off at 796.35708), or an appropriate way to show, for example, a geographical, sociocultural or topical distinction, because I don't have any Dewey classification guides on hand. (Can somebody please light the Cataloguer signal already?)
posted by maudlin at 3:44 PM on December 20, 2008

OK, librarian, not a cataloger, had a cataloging class in library school, way more familiar with Library of Congress than Dewey classification.

Your question kind of presumes that 796.3570 and 796.357 are equal, or at least equivalent, and they're not. Each position in a classification number has meaning, they're not like regular numbers you do math with. The answer to "what does this particular zero mean" lies in a full dewey decimal guide, which I can't seem to find online. When we used them in library school about 4 years ago, it was a many-volumed set of giant books.

I can find some non-exhaustive lists that might help you understand the system, though. Using your number as an example, all 7xx numbers are "Arts". 79x is "Recreational and performing arts". 796.x is "Athletic & outdoor sports & games". 796.3x is "Ball games". See how each digit adds specificity?

Additionally, there are some meaningful subdivisions that can be tacked on to the end of the subject classifications. For example, .03 = encyclopedias and dictionaries, so 796.303 would be an encyclopedia of ball games.

Finally, here are some useful caveats from one library's cataloging department:
# Cataloguing can't be learned in a day.
# Dewey is not a perfect system; not all books fit neatly into 1 number
# Some books can legitimately be catalogued in several numbers; choose the one most appropriate to the curriculum and the conditions in your school
# Always put a book in a number where it will get maximum usage; move excellent books if they don't seem to be used
# Bend the rules to suit local needs

which may help explain why there isn't exactly one right answer to your question, why multiple books have the same number, and why some libraries give this book a different number.
posted by donnagirl at 4:35 PM on December 20, 2008 [4 favorites]

Thank you all for your knowledgeable answers. This question has kept my reference librarian's nose out of his magazine all afternoon, and has further piqued my curiousity regarding classification systems. Very cool stuff.

Anyway, Mr. Ref. Lib. has been asking around, and he finally found someone here willing to admit to being a cataloguer. Her explanation of the mistake was that the assistant doing the cataloging was probably told to cut off all catalog numbers in that section after the 4th digit east of the decimal, which jives with maudlin's answer. The book's call number should have either included the following 8 or lopped off the 0. As it stands the trailing zero has no meaning, whereas if it were followed by another number it would take on whatever additional topical/etc. specifications that number called.
posted by saguaro at 5:14 PM on December 20, 2008

donnagirl has it. The long answer requires books on hand and stuff.

The cataloger at your library was wrong, but that is common.
posted by QIbHom at 6:40 AM on December 22, 2008

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