Cataloging and Classification/Other subject controlled vocabularies

Word-based classification


Several public libraries have explored the option of "word-based" classification in the 2000s and 2010s. Instead of grouping books using complex strings of numbers, as they would when using the Dewey Decimal system, they instead categorize books using regular language terms. Many libraries that use these "word-based" systems base their controlled vocabulary on the Book Industry Standards and Communications Subject Codes (BISAC). Though BISAC, like Dewey, offers complex alphanumeric strings for categorization, "Dewey-free" libraries generally use only the full English terms when categorizing books.

A comparison the BISAC 2012 Subject Headings and Dewey Decimal Classification 23rd edition
BISAC text Dewey number Dewey text
NON-CLASSIFIABLE 001.942 Generalities / Controversial knowledge / Mysteries / Unidentified flying objects (UFOs)
PHILOSOPHY / Eastern 181.114 Philosophy and psychology / Ancient, medieval & eastern philosophy / Far East and South Asia / China and Korea / Taoist philosophy
BIBLES 220 Religion / The [Christian] Bible
RELIGION / Islam / Koran & Sacred Writings 297.125 Religion / Other religions / Islam, Babism, Bahai Faith / Sources / Koran and Hadith / Hadith
SOCIAL SCIENCE / Gay Studies 306.7663 Social sciences / Culture / Sexual relations / Sexual orientation / Homosexuality / Lesbianism
FOREIGN LANGUAGE STUDY / Korean 495.7 Languages / Other languages / Languages of east and southeast Asia / Korean
NATURE / Animals / Horses 599.6657 Zoology / Mammals / Ungulates / Perissodactyla / Equidae / Zebras
PETS / Horses 636.1 Agriculture / animal husbandry / Equines
SPORTS & RECREATION / Soccer 796.334 Arts & recreation / Sports and games / Athletic and outdoor sports / Ball games / Inflated ball driven by foot / Soccer (Association football)
POETRY / African [for Nigerian poetry written in English] 821 Literature / English & Old English literatures / Poetry [for Nigerian poetry written in English]
HISTORY / United States / Civil War Period (1850-1877) 973.3 History / North America / United States / Administration of Abraham Lincoln, 1861-1865
HISTORY / Europe / Russia & the Former Soviet Union 947.0841 History / Europe / Russia and Eastern Europe / Russia / 1917-1991 / Period of Revolutions

A quick comparison of the two systems provides some interesting contrasts. Dewey, as a rule, takes far more subcategories to express a concept than BISAC does (look at the long, complicated categorization necessary for denoting Soccer in Dewey). On the other hand, BISAC's relative simplicity means that several concepts can't be expressed exactly (UFOs, Taoist philosophy, Hadith, Lesbians, Zebras, Russian Revolution). Both show a bias towards the United States (the American Civil War is simpler to express in both systems than the Russian Revolution) and other colonial powers (neither system is capable of expressing the concept of Nigerian Poetry). A bias towards Christianity is also evident (both provide very simple expressions for Christian Bibles, but not for the Muslim Hadith).

Advocates of BISAC-based systems say that abandoning Dewey's unintuitive numeric strings in favor of BISAC's simpler categorizations makes non-fiction collections easier for patrons to browse by themselves. Skeptics point to the difficulty of expressing exact concepts in BISAC's general categories, and say that using such broad categories makes it more difficult to find a particular book. Both advocates and skeptics agree that BISAC is better suited to small public libraries with smaller collections, where each of BISAC's categories will include dozens, rather than hundreds, of books.