If the resource centre is very small, users will be able to find the materials they need by browsing (looking at) the shelves. Otherwise, the resource centre will need a card catalogue or computer database, which contains details of materials in the collection and indicates where to find them on the shelves. Information on databases is given in Section 6.8.
A system for describing the content of each material will need to be developed before details of materials can be included in a catalogue or computer database. The best way is to have a list of ‘keywords’, and describe each material using several keywords from the list. For example, the keywords used by Healthlink Worldwide’s resource centre to describe the book, Where there is no doctor, are:
community health care / traditional health care / community health workers / diagnosis / diseases / management & treatment
Keywords lists and thesauri (lists of terms used to describe different subjects) are called ‘controlled vocabulary’, because they specify which terms (words or short phrases) are used for describing materials. Most keywords lists also specify terms that are not used, and suggest terms to use instead.
5.3.1 Choosing a keywords list
Resource centres can develop their own keywords lists (see Section 5.3.3), or obtain and adapt standard keywords lists.
Both general and specialist lists are available. General lists include the Library of Congress Subject Headings and Sears’ Subject Headings. Specialist lists include the UNESCO Macro-thesaurus, National Library of Medicine Medical Subject Headings (MeSH), and Healthlink Worldwide’s Keywords List. Healthlink Worldwide’s list, which was originally compiled in the mid-1980s, is regularly revised to incorporate new subject areas reflecting emerging health issues. The list is used by many organisations in either its original or an adapted form.
5.3.2 How to assign keywords
To assign keywords, look at the material carefully to identify the main subjects covered. Do not rely on the title. For books and other print materials, look at the title page, list of contents and introduction. For audiovisual materials, look at the title, description and any accompanying materials, and by watching a video, listening to an audio cassette, or looking at slides.
Notice which sections or chapters are longest, or which may be of special interest to users of the resource centre. Then assign keywords.
Start with general terms and move on to more specific terms to describe the material’s subject matter. Use as many keywords as necessary. However, remember that users will expect to find useful information on the subjects indicated by keywords.
To choose keywords, consider:
- the main subject
- related subject(s)
- the group of people that the material describes, such as street children, women, community health workers
- potential target audience
- the focus or purpose, such as research, planning, evaluation or training.
If you are using a computer database, or have sufficient space for extra catalogue cards, you could also include keywords to indicate the type of language, such as technical or non-technical.
5.3.3 How to produce a keywords list
To produce a keywords list for your resource centre:
1. List key terms (words or short phrases) that describe the main subject areas covered by the resource centre.
2. Add terms that describe more general and less common subject areas.
3. Explain any confusing terms in ‘scope notes’ (notes on the meaning of a keyword, and how it should be used).
4. Add cross-reference notes (notes indicating additional keywords that could be used to describe related subjects, or keywords to use if the term is not a keyword).
You can see examples of scope notes and cross-reference notes in the sample of Healthlink Worldwide’s Keywords List in Section 5.3.4.
Getting things right with a ‘home-made’ keywords list is not always easy. You may need to add new terms to the list if you cannot find a term that describes the material that you are cataloguing.
When first developing a list, it is sensible to review the terms regularly. Once the list is established, review additions and possible changes about once a year.
5.3.4 Sample of Healthlink Worldwide Keywords List
The Healthlink Worldwide Keywords List is a list of all the terms used in the Healthlink Worldwide bibliographic database.
The list is divided into two columns. The left-hand column lists, in alphabetical order, the keywords to use (in bold capital letters) and terms not to be used as keywords (in lower case letters). The right-hand column shows keywords to use (in capital letters) instead of the terms that should not be used. It also includes notes on how and when to use keywords, and related keywords (in capital letters).
The notes next to ‘ACCESS’ are scope notes, explaining how to use the keyword. The notes next to ‘ACCIDENTS’ are cross-reference notes which refer to another, related keyword which could also be used if relevant. The notes next to 'adolescents' are cross-reference notes showing which keyword to use, since 'adolescents' is not a keyword.
