Using the thesaurus

Descriptors and non-descriptors

The African Studies Thesaurus is a searchable online tool, with direct links to the ASC catalogue. It contains some 12,100 terms, of which some 5,200 are descriptors or preferred terms. The remaining terms, non-descriptors or non-preferred terms, provide additional entry points to the descriptors. In the alphabetical indexes, descriptors are indicated in regular font, non-descriptors in italics. Selecting a non-descriptor will lead you to the descriptor or preferred term.

Browsing A–Z index or searching

Descriptors can be found by browsing the main A-Z index, or by typing a word in the search field. Clicking on a letter in the A-Z list leads to an alphabetical list of all the terms which begin with that particular letter. Alternatively, typing a word in the search field and clicking the ‘search thesaurus’ button produces a list of both descriptors and non-descriptors beginning with that word. The list may span more than one page. If a term is not found, you will be directed to the closest terms in the alphabetical index.

Individual records

Relationships between descriptors are hierarchical (broader terms, narrower terms) or non-hierarchical (related terms). All relationships are reciprocal. Descriptor records may further contain a description or definition of the term (scope note), specific directions for use (user tips), a link to a relevant website (weblink), or an indication of when the descriptor was introduced (indexing history). Information is presented in the following order:

• Scope note
• User tips
• Used for
• Broader terms
• Narrower terms
• Related terms
• Weblink
• Indexing history

Note that only the broader and narrower terms one level immediately above or below the descriptor are displayed. Each descriptor record contains a direct link to the ASC catalogue.

Search catalogue

Clicking on ‘Search catalogue’ launches a search in the ASC catalogue and you will leave the thesaurus. A search from the thesaurus is equivalent to using the search key ‘ASC subject heading (exact)’ in the catalogue’s drop-down menu even though another search key may be displayed. Descriptors are always in English, also in the Dutch version of the catalogue.

If a search produces few or no hits we suggest you check out the descriptor’s Indexing history in the thesaurus. Some descriptors are relatively new and you may have to use another descriptor, or a combination of descriptors, to retrieve titles which were indexed before the descriptor was introduced. For example, to find publications on gender inequality indexed before 2006, you will need to use the descriptor gender relations.

If there is no Search catalogue option the descriptor in question is not used for indexing. Such descriptors are broad geographical and form headings which have been included in the thesaurus to group more specific terms. For example, for almost every country there are geographical headings for languages, peoples, polities and political parties. Thus the descriptor Ugandan peoples groups all the ethnic groups in Uganda (Narrower terms) which are indexed by name. You will find titles about each of these ethnic groups in the catalogue. To find titles about all Ugandan ethnic groups, you will need to search for each group separately and cumulate the results.

If you wish to search with more than one descriptor we suggest you search directly in the catalogue using the advanced search mode (select in navigation bar) and the search key ‘ASC subject heading (exact)’ in the drop-down menu.