If I understand her correctly, Kathryn King, the Adult Materials Selector of the Ft. Worth Public Library, deals with collections instead of books in her library. By that, I mean she analyzes collections first and sets goals for purchasing and weeding before contemplating individual books. Those goals are pretty specific, too. Instead of getting rid of a certain number of books in a Dewey area or genre area when weeding, she wants to get a certain number of a certain age range out so that (1) she is left with certain ratios of age to collection and (2) to balance annual relative use (RU = percentage of circulation divided by percentage of collection). Weeding may not be sufficient, so she will then have to add a certain number of new materials to get the age ratios right and balance the relative use of highly used collections. To extend the horticultural metaphor past "weeding," King is a "landscaper" instead of a "gardener."
At the Public Library Association Conference in Portland, King told about her customer-oriented work in the Thursday afternoon session I Have These Statistics - Now What: Getting Started on the Path of Collection Analysis. She began by defining several measures of the collection, all based on statistics drawn from the database of the circulation system. The great detail about very narrow segments was impressive. It all worked toward measuring relative use.
Here is how King sees relative use:
RU = 1 (The collection is meeting the demand.)
RU > 1 (The collection needs expansion.)
RU < 1 (The collection needs weeding.)
King reported that the Texas State Library recommends that 25 percent of a library collection needs to be materials published in the last five years. She thinks that is not good enough overall and particularly bad in specific critical areas, such as health, finance, travel, and decorating, where at least 70 percent should be from the past five years. With these Dewey subject areas, it is the content that is most in need of being current. Even in less critical areas, most of the items should be from the last ten or maybe twenty years. With these areas, the driving concern is style more than content. Libraries want to have books that look contemporary. In other words, nice jackets and color photos instead of old library bindings and 1950s illustrations.
One King statement really challenges the way many of us buy books. She said that to meet demand in high use Dewey areas, buying multiple copies of the best books serves better than buying single copies of many titles. When there are single copies, some readers will take them all, leaving none for the next reader. Multiple copies leaves items for second and third readers. Customers are better satisfied and circulation rises.
Another statement for us to mull over is that it is unfair to apply less stringent weeding criteria to less critical areas. If a selector says that every book in one area had to circulate within the year and in another area let books that sat for two or three years stay, that selector will actually be withdrawing better circulating books and reducing the overall collection relative use.
Ft. Worth puts copyright dates on all spine labels. Readers like knowing the dates and weeding is easier.
King said that weeding needs to be done even in years of reduced funding for purchasing new materials. The relative use needs to be kept in balance. Not weeding now makes more work later. In her opinion, it is better to have no books than bad books.
Collecting these statistics should be relatively easy if library selectors have a good integrated library system. King emphasized that collection analysis should be done to better serve the public and to have hard data when arguing for continuing financial support.