General
A study reported in 1977 at B rock University Library (Canada) of 532 titles from the university serials list that had International Standard Serial Numbers (ISSNs) reported both in Irregular Serials and Annuals: an International Directory (2nd issue) and in New Serial Titles showed that 32 (6.01%) titles did not have the same ISSN listed both places but instead had 2 different numbers listed. Of these 32, 30 (93.8%) had the “05” factor, i.e., the ISSN began with “05.” (Source)
Ibid. . . . showed that, of 497 serial titles taken from 10 “representative” publishers’ lists and searched in all the Bowker publications providing ISSNs (including Irregular Serials and Annuals: an International Directory, 2nd edition) and in New Serial Titles, 428 (86.1%) had ISSNs of which 398 titles had ISSNs reported in more than 1 publication. Of these 398 titles, 31 (7.79%) titles did not have the same ISSN listed in all publications but instead had different ISSN numbers listed. Of these 31, the “05” factor, i.e., the ISSN began with “05,” figured in 58.06% of the cases. (Source)
A study reported in 1977 of “Corrections to Previous ISSN Assignments” listed in Ulrich’s International Periodicals Directory, 15th edition, and in Irregular Serials and Annuals: an International Directory, 3rd edition, showed that using the “lower/lowest” ISSN did not lead to substantially greater agreement among sources. Specifically, of 67 ISSNs listed in Ulrich’s, 57 (85.1%) were the lower of the 2 assigned numbers; while of 44 ISSNs listed in Irregular, 25 (56.82%) were the lower of the 2 assigned numbers. (Source)
