"Making Visible the Invisible", a data visualization commissioned by the Seattle Central Library, operational since fall 2005

This database receives by the hour all of the checkouts of books, cds, DVDs, and other material that library patrons take out of the library. The data at the library is classified in two separate categories. Non-fiction items receive a Dewey Classfication System coding, explained here: Dewey Decimal Classes. Fictional items are classified in a different way. This visualization features the top 20 most active Dewey categories. Click on each of the categories to get the chronological list of titles checked out during the previous hour.

0028 books out of 0032 items checked out at 18:00, 02.06.2026

[0032] Total items checked out	[0021] Dewey (non-fiction) Books	[0007] Non-Dewey (fiction) Books
[0028] Total Books	[0003] Media (dvd, cd, etc.)	[0000] Misc

Dewey Decimal Classification Graph

This map highlights current circulating books according to their Dewey classification category in Generalities [0-99]; Philosophy & Psychology[100-199]; Religion [200-299]; Social Science [300-399]; Language [400-499]; Natural Science & Mathematics [500-599]; Technology & Applied Sciences [600-699]; Arts [700-799]; Literature [800-899]; Geography & History [900-999].

			The top 14 Dewey categories
	4		[747] Interior decoration
	2		[306] Culture + institutions
	2		[282] Roman Catholic Church
	2		[793] Indoor games + amusements
	2		[346] Private law
	1		[364] Criminology
	1		[271] Religious orders in church history
	1		[940] General history of Europe
	1		[347] Civil procedure + courts
	1		[248] Christian experience, practice, life
	1		[643] Housing + household equipment
	1		[150] Psychology
	1		[363] Other social problems + services
	1		[224] Prophetic books of Old Testament