Library+Maintenance

ICREW method for weeding from the Texas State Library. The new updated manual from 2008 is available in PDF format online at @https://www.tsl.state.tx.us/ld/pubs/crew/index.html There are 10 steps and the basic criteria for weeding are circulation (set a period of time in which item has not circulated) condition, outdated information, duplication of material - do you need the duplicate, uniqueness (keep if it is unique and needed).

There is a quick formula in the crew method to determine whether to keep materials. Plus there is a suggestion for the numbers for the formula by Dewey Class in the manual

Formula is

MUSTIE EXAMPLE 8/3MUSTIE = 8 years since latest copyright date 3 years since last circulation MUSTIE
 * 1) of years since latest copyright date/maximum time with no circulation

M = Misleading information (and/or factually inaccurate information)

U = Ugly (worn, dusty poor condition)

S = Superseded (with newer edition or a better book on the subject)

T = Trivial (of no discernable literary or scientific merit)

I = Irrelevant to the needs of your community

E = the material or information is available Elsewhere more expeditiously (Internet, Interlibrary Loan, etc.)