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Dewey Decimal System Day

From a young age, Melvil Dewey focused on organization, simplification, and efficiency. Born as "Melville" on today's date in 1851, he removed letters from his name he found unnecessary, becoming Melvil, which he believed was more efficient. He applied his vision for a more organized and efficient world at the Amherst College library, when he was given the task of reclassifying their books while working there as a student assistant at the age of 21. He developed his classification system using decimal numbers from Natale Battezzati's library card system and a structure developed by Sir Francis Bacon. First published in 1876, the Dewey Decimal Classification—commonly known as the Dewey Decimal System―revolutionized libraries, and became the main way that libraries classified books around the world. Today it is estimated that 200,000 libraries in 135 countries use the Dewey Decimal System.

Dewey's system organizes books into ten main classes or fields of knowledge, which are then divided into ten smaller, more specialized subcategories. Each of these ten subcategories can be further broken down into another 100 numbers after a decimal point. Revisions to the system have been made since it was created. For instance, computer science was not originally part of a class, as it did not exist. The system has been critiqued for being both Christian-centric and English-centric.

The main way books are categorized in libraries today is still by the Dewey Decimal System, although some libraries have switched to the Library of Congress Classification System (LCC). The Dewey Decimal System is monitored by the Online Computer Library Center. As for Melvil Dewey, he became known as the "Father of Modern Librarianship," and also became a proponent of the metric system, founding the American Metric Bureau. He has not been without controversy, however, and charges of antisemitism, racism, and sexual harassment have sullied his reputation. But on Dewey Decimal System Day we are not celebrating the man, but rather, the system of classification that he created that has made it easier to find a book at a library.

How to Observe Dewey Decimal System Day

One way to celebrate the day is to head to your local library and browse the nonfiction section while using the Dewey Decimal System. The ten classes of knowledge are as follows:

  • 000 - Computer science, information, and general works
  • 100 - Philosophy and psychology
  • 200 - Religion
  • 300 - Social sciences
  • 400 - Language
  • 500 - Science
  • 600 - Technology
  • 700 - Arts and recreation
  • 800 - Literature
  • 900 - History and geography

These classes are further divided into more specialized subcategories. Another way to celebrate the day could be to use the Dewey Decimal System to organize the books you have at home. The day could also be spent learning more about the system or about Dewey himself.

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