EBSCO maintains a Comprehensive Subject Index (CSI) of subject terms, which are applied to all articles indexed by EBSCO. The subject thesauri displayed on some EBSCOhost databases are discipline-specific subsets of this controlled vocabulary.
All indexing at EBSCO is based on rules created by the Library of Congress and the Anglo-American Cataloging rules. EBSCO's CSI is an expansion and adaptation of the Library of Congress Subject Headings database. As Library of Congress Subject Headings are created to cover the books received by that library, they describe broad subjects that have been considered at book level. To cover periodical content at an appropriate level of detail, and to cover subjects that may not yet have appeared in books, EBSCO creates additional subject headings that do not appear in the Library of Congress file. A professional team of taxonomists reviews the latest literature, subject-specific glossaries, current events, and other resources to ensure that subject headings are available to cover the wide span of literature indexed by EBSCO.
EBSCO’s subject headings are also continuously reviewed to ensure that they follow current usage. Subject headings attempt to convey concepts in natural language wherever possible, with exceptions to prevent ambiguity.
Following Library of Congress practice, EBSCO indexers expand on headings by applying subdivisions that refer to specific aspects of the topic. Subdivisions are taken from a standard list. For example, the CSI includes the root heading “Newspapers.” When appropriate, we expand on that heading by adding subdivisions to create new headings such as: “Newspapers – Awards,” “Newspapers – Reviews,” or “Newspapers – Taxation.” Thus, more specific headings can be systematically created to completely represent specific content.
Using the CSI’s more than 300,000 subject headings, plus approved subdivisions, indexers at EBSCO are able to select two to twelve headings that highlight the main point of the article being indexed. The number of headings will vary with the length and complexity of the article. By limiting the number of headings assigned to an article, EBSCO aids the researcher by ensuring that headings lead to articles that focus on the topic in question.
All EBSCO indexers strive toward product consistency and are trained on choosing topic-specific subject headings and presenting them hierarchically according to article type. Additionally, when a high-profile event is in the news, the Abstracting and Indexing group (A&I) at EBSCO reviews existing subject headings to determine the best descriptors for this event; these then are shared among all indexers to ensure that the subject is being indexed consistently within the team. If new headings are required to index a specific current event, the Taxonomy team will create terms for A&I to index that event.
By being vigilant about the selection process, EBSCO has assured that its headings are consistent and that its subject searching capabilities will be unparalleled in the marketplace.