Controlled Vocabulary: Using CINAHL and ERIC Subject Headings

• CINAHL Headings are the official controlled vocabulary for nursing, and they can be found under "CINAHL Headings" in that database.   In the ERIC database, you can identify ERIC subject headings or "descriptors" in the same way. CINAHL and ERIC subject headings are referred to as “controlled vocabulary." Controlled vocabulary refers to the official ways of referring to topics within a discipline.
• Each article or document in CINAHL, ERIC and other databases is associated with a one or more subject terms that describe the content of that article or document.
• For each concept you enter, you will be directed to the correct ERIC descriptor or CINAHL subject heading, its definition (“scope”), synonyms, and related concepts, including narrower and broader terms. Note down any headings or terms that seem relevant to your concept and research question. Remember that broader or more specific words or phrases can be used to expand or refine your search results.

Uncontrolled Vocabulary: Cast a Wider Net

• Next, reflect on your research question and concepts and write down any related keywords or keyphrases (“uncontrolled vocabulary”) that come to mind. Draw upon your own expertise and knowledge of the nursing field for additional terms.
• Uncontrolled vocabulary is often useful to describe very new/innovative or obscure topics, concepts or ideas, for which subject headings have not been assigned.
• Terms can be harvested from articles, books or other sources of information on your topic.  You can also draw on your own knowledge and everyday parlance on the topic.

Controlled Vocabulary + Uncontrolled Vocabulary = A Comprehensive Search

 It is strongly advised that you go through this process systematically for each concept, using a blank piece of paper OR the Nursing Education Search Strategy Worksheet (see tab on the Search Strategy guide), so that your search is both precise, and thorough.

• NOTE: you will not necessarily use all the terms that you write down. Use your own judgment and search style preference to determine what your final search strategy will look like.
• It is often necessary to use controlled vocabulary to construct a truly comprehensive search. For example, using the commonly used term will provide far fewer search results than the ERIC or CINAHL Heading.

The CINAHL Headings list is a very useful tool for determining your search vocabulary and learning how your topic is referred to in the literature. Each item in the database is assigned a set of subject terms or headings that describe the content of that item. There are more than 10,600 main subject headings as well as thousands of cross-references (for example, you'll see "used for" when one subject heading has been replaced for a new one). CINAHL Headings are updated annually by subject specialists. CINAHL accepts the U.S. National Library of Medicine's Medical Subject Headings (MeSH) as the standard vocabulary for disease, drug, anatomical, and physiological concepts.

CINAHL headings are arranged in a hierarchy, or Tree View that permits searching at various levels of detail from the most general level to more narrow levels to find the most precise terms. Tree views in CINAHL can simply be used to identify subject vocabulary OR can be used to construct your search in EBSCOHost. Tree Views can be used as a search builder, offering a menu of choices.

The Thesaurus of ERIC Descriptors is a controlled vocabulary - - a carefully selected list of education-related subject headings. ERIC assigns terms to ERIC records to organize them by subject and make them easier to retrieve through a search. Searching by Descriptors involves selecting relevant terms from this controlled vocabulary to locate information on your topic.

While you can also search ERIC using keywords of your choosing, you will get more precise search results if you use Thesaurus subject terms. That's because searching by keywords matches the exact words found in a record, whether or not they are used in the same context as your topic, while searching by Descriptors allows you to locate records by subject, regardless of the terminology the author may have used. The ERIC Thesaurus will help you save time by reducing guesswork and trial-and-error methods.