Source Publication (e.g., journal title)
Controlled vocabulary indexing was developed well over a century ago to provide a consistent way for users to search for information, but human-assigned indexing has always been labor-intensive and costly. Because of the importance of indexing, two major information companies are trying automated approaches.
Tenopir, Carol, "Human or Automated, Indexing is Important" (1999). School of Information Sciences -- Faculty Publications and Other Works.