National Library of Medicine

The landmark citation method is a new collection assessment method based on the citation record of a single landmark article. This citation record is developed by identifying sources which cite the landmark article. A bibliography, extracted from the citation record, is then used to complete an assessment of the collection. This method was developed and used to assess the biotechnology collection of the National Library of Medicine. The information gained from this study, in addition to demonstrating the technique, also provided insight into the evolution of the biotechnology literature. Collection assessment can be defined as measuring or determining the degree to which a library has acquired the books, journals, and other materials it intended to acquire, especially in relation to a written policy statement. The practice is common; indeed, researchers have noted that "collections have been evaluated since libraries began building them, and the literature related to the many methods available is large " [1]. Mosher traces programmatic collection evaluation back to the mid-nineteenth century, to Jewett's 1849 comparative analysis of citations in sev