Knowledge Organization (KO) is published by IMR Press from Volume 52 Issue 1 (2025). Previous articles were published by another publisher under the CC-BY licence, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement.
1 University of Pavia, Science and Technology Library – Pavia, Italy
2 Linnaeus University, Department of Library and Information Science, School of Cultural Sciences, Faculty of Arts and Humanities – Kalmar and Vaxjo, Sweden
3 Edinburgh Napier University – Edinburgh, United Kingdom of Great Britain and Northern Ireland
4 Kent State University, School of Information – Kent, United States
5 University of Alberta, School of Library and Information Studies – Alberta, Canada
6 UDC Consortium – Hague, Netherlands and University of Zagreb, Department of Information and Communication Sciences, Zagreb – Croatia
Abstract
This article addresses the underutilization of knowledge organization systems (KOS) elements in online library catalogs, hindering effective subject-based search and discovery. It highlights the International Society for Knowledge Organization's initiative to develop metadata guidelines for library catalog procurement, focusing on maximizing the value of subject metadata from classification systems and controlled vocabularies. The paper discusses the rationale for quality subject access, proposes desirable search functionalities based on research, explores implementation challenges, and outlines future developments. The conclusion emphasizes the importance of providing quality subject access in digital services and calls for further research on interface design, guideline adoption, KOS evolution, and the impact of language models on subject metadata use. The work underscores the need for applying controlled vocabularies in search interfaces across libraries, archives, and museums while acknowledging the complementary role of alternative approaches like social tagging and automatic indexing. Extensive future research is suggested to implement search functionalities, promote guidelines adoption, enhance KOS evolution, and assess the influence of language models on subject metadata utilization.