ABSTRACT
After an introduction that addresses the means people use to search for information, this entry articulates the principles underlying various subject access options, including both controlled vocabulary systems and classification. It begins with a brief history of subject access provisions, including an account of the impact of automation, and goes on to discuss in some detail the principles underlying American library practice in respect to subject access. It then, briefly, describes selected subject-access schemes (including both subject heading lists and classification systems) in terms of how they reflect the principles presented, and how well they fulfill their stated functions.
