The advent of technology has made it possible to transfer print periodical indexes (e.g., Readers' Guide to Periodical Literature, Humanities Index, etc.) to an electronic format so that now they are often called periodical databases. Originally these online periodical indexes, or databases, were comprised of citations only just as they had been in their print form. Technology progressed so that abstracts or summaries of the articles were added to the citations. Now more and more periodical databases are adding full-text articles so that users can download to a data disk or print an entire article directly from the online periodical index.
Databases that include full-text articles take articles that originally appeared in a magazine, journal, or book, and reproduce them online. A citation telling the user where the article originally appeared is given at the top of the record. Many periodical databases with full-text articles also include an abstract or summary of the article.
As with the library catalog, simple searches can be done using author, title, subject, and words or phrase. In contrast to subject searching in which you look for an article about a certain topic, the only requirement in keyword searching is that the word is mentioned somewhere in the record. A keyword search on the topic fertility conducted in different databases yielded the following results. Notice the differences in the subjects fields. This is a good example of how different databases have different controlled vocabularies. Conducting a keyword search can help you become familiar with a database's controlled vocabulary as well as develop ideas for focusing a topic.
Note that just because a database states full-text does not mean all the records have the whole or full-text article. In some cases only the citation is available. In a periodical database a citation directs you to the original article, book chapter, dissertation, or paper. Normally the citation information includes the author, title, publisher, place of publication, edition, subjects, and page numbers. Often, an abstract (summary) of the article will be included.
Locating articles for which you have only a citation is a two-step process. After retrieving several citations on your topic you must check the library catalog to verify if the library subscribes to the publications on your list.