Systematic evaluation of a library's collection can be a useful tool for collection development. After reviewing three evaluation methods and their usefulness for our small academic library, I undertook a usage-based evaluation, focusing on narrow segments of our collection that served specific undergraduate courses. For each section, I collected data on the number of books owned, number of checkouts in the past four years, and number of unique books used. Using examples from the data, I discuss possible ways to interpret and act on the data. I also note how the knowledge gained from this evaluation fits into the larger toolkit of librarian competencies for collection development.