Critical Analysis of the Iranian Expansions of Dewey Decimal Classification Edition 22

The aim of this research was to critically study the Iranian expansions of the Dewey Decimal Classification in three sections i.e. standard subdivisions, the schedules, and the relative index. Methodology/Approach: This is a developmental research based on records and comparisons. Despite the claim that the Iranian literature expansion is up-to-date and matched to the 21st edition of the Dewey Classification, in the standard subdivision table of this expansion, 80.30 percent of the numbers together with the expressions in front of them have changed in comparison with edition 21 of Dewey Classification. In the schedules, general principles are similar to those of Dewey edition 18, while this structure has significantly altered in Edition 22. The expansion of Islam also indicates the differences between the structure and numbers presented in this expansion for the Islam subject field and the structure and numbers available in the Dewey in its present edition i.e. edition 22, for this field. The third edition of the Iran History expansion, as its introduction claims, had been compared with Dewey 21 and edited wherever required. 89.47 percent of the numbers in the history expansion have completely changed in comparison with edition 20 and 88.38 have completely changed compared with Edition 21. The last edition of the Iranian languages expansion (i.e. edition 2) conforms to Dewey Edition 19. Statistical findings from the standard subdivisions tables show that 27.86 percent of the numbers in the Iranian languages expansion have undergone significant change compared with Dewey Edition 19. Analysis of the schedules of literature, history, and Iranian languages expansions along with comparisons with the main outline of the Dewey classification in classes 800, 900, and 400 and comparing them with structures of schedules in the literature, history, and Iranian languages expansions indicate a limit in numbering through the literature, history, and Iranian languages expansions. The Iranian expansions of the Dewey classification need to be updated based on the universal approach used in the main text of the Dewey classification. By implementing the suggestions of this research the Iranian expansions may be combined into one volume. Some suggestions are provided for changing the structure of schedules of these expansions and therefore improving the status of numbering by them.