Columbia-Greene Community College (Hudson, New York) takes a yearly 10% statistical sample of its entire circulating collection, noting the call number, acquisition year, and circulation record of each book, in order to determine the pattern of book use over the preceding 2.5 years, and to facilitate the development of an acquisition pattern that accurately reflects need. Additional useful findings which resulted from the 1986 sample are that 79% of the library's books have been used at least once since January 1977, 48% have been used in the last 2.5 years, and 78% of the books acquired since 1985 have already been used--a measure of the library's effectiveness in book selection--and that, on the average, newer books circulate far more frequently than older ones. The library also uses survey findings to determine specific areas in which purchases need to be made, and to obtain an overview of collection activity. Data from the survey covering the 2.5-year period from January 1984 through June 1986 is presented in two graphs which illustrate the percent of books that were used in each classification and the intensity of use for that period. (KM)