SUBJECT-SPECIFIC PERIODICAL DATABASES

Subject periodical databases are used in the same way as general periodical databases, but the publications indexed tend to be more scholarly and professional journals and subject magazines all focused on a particular subject area. While more and more general-interest magazines are being produced in computerized full-text formats, a lower percentage of academic journals have been made available in electronic full-text versions. Subject periodical databases, therefore, usually include fewer full-text articles. Most subject periodical databases do, however, include abstracts.

Some subject periodical databases are very comprehensive, trying to index almost every journal published in a particular field of study, while others are more selective, including a limited number of the more important, less specialized magazines and journals in a subject area. H.W. Wilson Company, the company that publishes Readers' Guide, produces a number of the more selective types of periodical databases, including Education Full Text, General Science Full Text, Humanities Full Text, Readers' Guide Full Text, Social Sciences Full Text and Wilson Business Full Text . All of these databases are now available on Wilson's Web site (called WilsonWeb) in a single combined database called OminFile FullText Mega. The WilsonWeb site (http://hwwilsonweb.com) is freely available from any computers on campus. Students in LSCI 105 can access the site from off-campus, but a Username and Password (available from the instructor) are required to log in. These commonly-used subject periodical databases are especially oriented toward undergraduate students.

The list of periodical indexes covering specific subject areas is extensive and includes virtually every field of study. Some of the more comprehensive, most well-known subject databases (all of which include abstracts but no full-text) include: Psychological Abstracts, Sociological Abstracts, BIOSIS (biology), Medline (medicine), ERIC: Educational Resources Information Clearinghouse (education), PAIS: Public Affairs Information Service (political science), ABI/Inform (business information), America: History and Life (American history), Historical Abstracts (world history) and INSPEC (physics, electronics and computing.) Although not limited to any specific field, Dissertation Abstracts is an important academic database which indexes and abstracts Ph.D. dissertations and M.A. theses in all subject areas.

Two of these major subject databases, both of which are produced by federal government agencies, are now available for free on the Internet. Medline, from the National Library of Medicine, is available at: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed. ERIC, from the U.S. Department of Education, can be accessed at: http://ericir.syr.edu/Eric/

Another periodical index that is available on the Web is the UnCover database. This unique database includes basic citation information for articles from over 17,000 journals in all subject areas going back to Fall 1988. No subject indexing is included so you can only search for keywords from the titles of articles or of journals or authors' names. Searching the database is free. Uncover also includes a fee service that will fax you the full text of articles from the database. A typical charge for faxing one article is about $12.00. Uncover is accessible at: http://uncweb.carl.org.

Selecting and Evaluating Periodical Indexes and Databases

The distinctions between different types of periodical databases often becomes blurred as more and more varied information and features are added to many databases. As more periodicals become available in full-text, for example, they are often added to indexes that previously only contained abstracts. Likewise, abstracts are now being provided by indexes that did not offer that feature in the past. The number and types of publications covered by many indexes are increasing rapidly so that it is not uncommon to find individual databases which include newspapers, popular and subject magazines, and even some scholarly journals. Many periodical abstracting services covering particular subject areas also include books, dissertations and other documents in their coverage.

It is always important to read a description of how many and what types of sources are covered by a particular index. Scanning the list of periodicals indexed gives the user an even better idea of the type of information provided by an index. Print indexes usually include the list of periodicals they index at the front of each volume. Web database periodical lists are usually available on the Web as well and are usually linked to directly from the database.

Lists of periodicals indexed by a database often do not indicate whether all articles from each of the periodicals are actually indexed. Many databases only index the "main" articles (excluding articles such as columns, reviews, editorials, letters or articles less than a certain length) from a majority of the periodicals (called "selective" indexing) and designate a smaller number of periodicals considered more significant to have all articles indexed (referred to as "cover-to-cover indexing.")

Dates of coverage listed for a periodical database can also sometimes be misleading. It is important to check when a database has been most recently updated, but the given date may not indicate the currency of the periodicals actually indexed. The dates of the periodicals covered in a database often vary considerably, depending on the type of database. Online newspapers, for example, are commonly available within a day of their publication--sometimes even the same day--while some academic abstracts often take over a year to index many journals.

Retrospective coverage--how many years back an index covers--is often one significant advantage of print indexes. The New York Times Index--with coverage back to 1851-- and the Readers' Guide--going back to the turn of the century--are two of the oldest indexes available. Very few computerized periodical databases provide retrospective coverage before the 1960's at the very earliest. (Some of the earliest coverage among general interest databases includes the online version of Magazine Index, with some coverage as far back as 1959 and the New York Times on the Nexis service, back to 1969.)


Questions to Ask When Selecting a Periodical Index or Database
1) Subject coverage: General or subject-oriented? Popular or academic emphasis? Is a list of periodicals indexed available?

2) Type of records: Citation, abstract or full-text?

3) Dates of coverage: How current? How far back?

4) Extent of articles included: Cover-to-cover or selective?

5) Quality of subject indexing: Is controlled vocabulary used? If so, is a thesaurus or subject index available? What is average number of search terms per article?

6) Availability: Is it available at your local library? in print? on CD-ROM? online? Can you access it from home? Is it freely available on the Internet?



Finding Which Library Carries a Periodical

Unlike books in a catalog, the periodicals included in indexes are not based on the holdings of a particular library. To find out which periodicals are carried by a particular library, you can use a "periodicals list" or "serials list". Some libraries include their periodicals in their main catalog, but many maintain a separate alphabetical list of periodical titles. These lists often indicate where each periodical is located in the library. In many libraries older copies of periodicals are available on microfiche or microfilm or, in some cases, they are bound (like books) and are shelved in the regular stacks. In other libraries, back issues are kept in a separate periodicals section. Recent issues of periodicals ("current periodicals") are virtually always kept in a separate section. Many libraries also provide a subject list of their periodicals in addition to the titles list. To find out which periodicals are carried by other libraries in an area, you can often refer to a "union list of periodicals", which includes all periodicals carried by a group of different libraries.

Libraries' periodicals lists are also commonly available on most libraries' online catalogs. In some catalogs, periodical titles are listed in the same index as book titles and in some catalogs periodical titles are listed in a separate indexes.



Finding Information About Periodicals

Several other important reference sources provide useful information about periodicals in any library. Ulrich's International Periodical Directory is an excellent guide to find out what periodicals are published in a particular subject area beyond those carried by specific libraries. Ulrich's lists around 120,000 periodicals by title and by broad subject areas. For each periodical title, Ulrich's includes basic bibliographical information, such as the address of the publisher, frequency of publication (monthly, quarterly, etc.) and in which indexes the periodical is included. Ulrich's is available in print, on CD-ROM and online. See the database sections for more information on using Ulrich's. The Serials Directory, published by Ebsco, the country's largest periodical distributor, is a competing publication that provides the same type of information as Ulrich's.

Magazines for Libraries

The basic information about each periodical which is provided by Ulrich's and the Serials Directory can be very helpful for certain purposes, but what if you want to know more about a periodical, such as its political perspective and the type of articles it publishes? Magazines for Libraries, an invaluable single volume reference source provides this type of important information. Magazines for Libraries lists about 6500 of the most important magazines in all fields. This source is especially useful because it includes detailed annotations thoroughly describing each of the publications listed. It is updated every three to four years and is available only in print.

In addition to the descriptive annotations, Magazines for Libraries also provides publication information about each periodical that can be useful when evaluating the publication. The information for each title includes:

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last revised: 2-22-99 by Eric Brenner, Skyline College, San Bruno, CA

These materials may be used for educational purposes if you inform and credit the author and cite the source as: LSCI 105 Online Research. All commercial rights are reserved. To contact the author, send comments or suggestions to: Eric Brenner at brenner@smcccd.cc.ca.us