Rule of thumb re age of school library collection

[Diane Holzheimer <DFHolzheim@AOL.COM>]

Dear LM_Netters--; I need some information. I am aware of the Massachusetts
state standards regarding the amount of money spent on school library
materials as a percentage of the total of per pupil expenditure in the
community. (By the way, is this figure supposed to include the special
education budget? )But what about the age of the library book collection? I
seem to recall reading somewhere that 10% of the book collection should be
weeded, and 10% replaced each year. Is this a figment of my imagination? Are
there different standards for fiction, non-fiction, reference, technology? If
I did read this rule of thumb, was it someone else's pipe-dream or did it
have any weight behind it? Would love to have this data or reference by
Monday evening. Thank you so much. Diane Holzheimer (dfholzheim@aol.com)