Abstract
Citation data from the 1975 and 1976 Journal Citation Reports were used to develop a `computer science impact factor' for ranking `core' journals in computer science. The starting set of source journals included Communications of the ACM, Computer, IEEE Transactions on Computers, and Journal of the Association for Computing Machinery, to which Computer Journal was added in iteration. The problems and limitations of citation analysis are discussed and results are compared with a previous analysis (K. Subramanyam, IEEE Trans. Prof. Commun., vol.PC-19, no.2, p.22-25, Dec. 1976). Librarians' use of the results should be made in the light of their own experience of user requirements.