Library and Information Science

This study attempts to compare the indexing in medical online bibliographic databases, EMBASE, JMEDICINE, and MEDLINE. We conducted tests concerning “the extent to which indexing terms link related documents”, “the extent to which indexing terms discriminate among these sets with in the database”, and “the extent to which terms discriminate finely among individual documents”, through the practical method suggested by White and Griffith in their paper “Quality of indexing in online data base” (Information Processing and Management, 23(3): 211–224 (1987)). We also conducted qualitative comparison on indexing terms assigned by these databases, with reference to the characteristics of their vocabularies and size of each database. Based upon the comparison, some advantages and disadvantages of indexing and/or controled vocabularies of three databases, several factors affect to the quality of indexing, and effectiveness of “devices” for indexing in the large operative databases are discussed.