Identification and Analysis of Conceptual Structure of Persian Subject Headings in Comparison with the Library of Congress Classification System and Academic System of Iran

This paper aims to discover the conceptual system of Persian Subject Headings (PSH) through the content analysis method. In order to discover the PSH's global hierarchical structure (GHS), all PSH records (84545 records) were investigated. Conceptual system of PSH was compared to the both Academic system of Iran and Library of Congress Classification system (LCC). Findings show strong relationships between PSH and LCC in Science (%19.5), Technology (%14.4), Social Sciences (%10.6) Medicine (%9.5) and Philosophy and Psychology (%6.6) classes. Identifying the hierarchical structures (tree structures) embedded in the entire PSH, 241 trees were found. Large trees and top headings (e.g. Medicine and Psychology, Sociology, Philosophy, Contracts, Founding, Mathematics, Management, law and …) were selected as the representation of the conceptual system of PSH to compare with the two other conceptual systems in this study. It shows that only %21.05 of top headings match the academic system of Iran and it is narrower than it. It means that a limited part of the academic system has been represented in PSH. The matching rate of top headings with the LCC is %71.05. In conclusion, the conceptual system of PSH is narrower than it is expected. It is recommended to correct the errors and enrich both its relational structure and conceptual system.