"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.

2219 books out of 3499 items checked out at 14:00, 01.05.2019

[3499] Total items checked out	[1113] Dewey (non-fiction) Books	[1106] Non-Dewey (fiction) Books
[2219] Total Books	[1135] Media (dvd, cd, etc.)	[0010] 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 20 Dewey categories
	146		[741] Drawing + drawings
	92		[641] Food + drink
	27		[398] Folklore
	24		[973] General history of North America United States
	23		[917] North America
	22		[616] Diseases
	19		[746] Textile arts
	19		[306] Culture + institutions
	18		[305] Social groups
	18		[658] General management
	17		[155] Differential + developmental psychology
	17		[613] Promotion of health
	17		[551] Geology, hydrology, meteorology
	16		[932] History of ancient world Egypt
	16		[158] Applied psychology
	15		[745] Decorative arts
	14		[811] Poetry
	13		[599] Mammalia (Mammals)
	12		[636] Animal husbandry
	11		[796] Athletic + outdoor sports + games