Controlled, In Control, and Out of Control: The Effects of Different Forms of Vocabulary Control on the Subject Indexing and Subject Tagging Processes

Abstract: Subject indexing, the process of determining what a document is about and then translating that “aboutness” into a representation in an indexing language, is fundamental to library cataloging.

Subject indexing has historically relied on controlled vocabularies to standardize language and to optimize information retrieval; however, controlled vocabularies have faced criticism for reinforcing systemic biases, for being slow to adapt, and for not reflecting the language and values of many people, especially those from marginalized and underrepresented groups. The emergence of folksonomies in the Web 2.0 era presented a clear contrast to rigorous vocabulary control and promised a more “democratic” form of knowledge organization that could reflect natural language, adapt quickly, and potentially avoid problems with systemic bias. Folksonomies and social tagging were criticized, though, for being too “uncontrolled” and, therefore, less effective as information retrieval indexes.

This study aims to update and enrich this comparison of vocabulary control in subject indexing and tagging by identifying five forms of vocabulary control in use today (minimal control, passive control, post hoc control, flexible control, and rigid control), and studying their effect on the subject indexing and subject tagging processes from the perspective of indexers and taggers.

The study uses a mixed methods approach—including a survey, a think-aloud protocol that is employed while participants index and tag documents, and a retrospective interview—to better understand participants’ actions, thoughts, and reactions during the indexing and tagging process. The study explores how controlled vocabularies make participants feel controlled, in control, or out of control while they index and tag; measures how different forms of vocabulary control affected coextensiveness between aboutness statements and indexing terms; and analyzes how these experiences inform the criticisms of controlled vocabularies, particularly for documents about racial and social justice. By building a robust understanding of the effects of different forms of vocabulary control on the subject indexing and subject tagging processes, this study seeks to help the designers of knowledge organization systems and controlled vocabularies to better and more equitably serve indexers, taggers, information seekers, and the information being indexed and tagged. 

Supervisory Committee

Chair: Joseph T. Tennis, Professor, Associate Dean for Faculty Affairs, Executive Director of Administrative Services
GSR: John Gennari, Graduate Program Director and Professor, Biomedical Informatics and Medical Education
Member: Nicholas Weber, Assistant Professor
Member: Marika Cifor, Assistant Professor