This discussion of the use of citation frequency data in judging a cluster or an entire collection of journals in academic libraries discusses the rationale for this methodology, and illustrates its application by examining citation counts in ISI's Journal Citation Reports (JCR) for periodicals in the area of communication research. The comparative merits of citation data and use/demand data are discussed, and it is concluded that citation frequency data are of more potential value to smaller academic libraries in evaluating their entire collection, and to larger libraries in evaluating sectors of journals and in storage decisions. Footnotes, three tables of data, and a list of 25 references are attached. (RAA)