A Study of Subject Indexing Consistency Between the National Library of Iran and Humanities Libraries in the Area of Iranian Studies

This study represents an attempt to compare indexing consistency between the catalogers of the National Library of Iran (NLI) on one side and 12 major academic and special libraries located in Tehran on the other. The research findings indicate that in 75% of the libraries the subject inconsistency values are 60% to 85%. In terms of subject classes, the consistency values are 10% to 35.2%, the mean of which is 22.5%. Moreover, the findings show that whenever the number of assigned terms increases, the probability of consistency decreases. This confirms Markey's findings in 1984.