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An important phase in the process of an information search is to become familiar with the concepts and terminology of the research field. You can find help in journal articles, reference works, handbooks, dictionaries, thesauruses. Reference works are publications similar to encyclopedias. Handbooks, on the other hand, contain extensive articles, which give a good preliminary understanding of the topic. Terminology and concepts for different disciplines can be found in thesauruses and dictionaries, which can also contain translations of these words into other languages.
Terminology related to the topic can be found from various sources of information such as reference books, dictionaries, basic literature in the discipline etc. It is often advisable to look for search terms also in databases related to the field and in their own thesauruses, as well as in articles.
Synonyms and alternative spellings and expressions
In order to achieve a comprehensive search result, it is worth thinking of synonyms, and alternative expressions and spelling forms for the terms. For instance, there are several synonyms and different expressions for 'bird flu'.
It is also useful to note alternative written forms and abbreviations for the search terms.
Some examples of differences between American and British English spelling and terminology.
When selecting search terms, it is also worth considering broadening or narrowing the context. Thesauruses describe the relationships between the descriptors, and this feature is useful when choosing search terms. Thesauruses and descriptors in them are database specific.
The metallurgical thesaurus in ProQuest presents, in addition to the descriptors, broader terms and narrower terms as well as related terms.
Image source: ProQuest <http://search.proquest.com> 25.7.2013
Thesauruses often tell you also what descriptor is used for a particular concept. As can be seen in the thesaurus from the ProQuest database,'vision systems' is used as the descriptor for the term 'machine vision' in this database, whereas the Ebsco Academic Search uses the term'computer vision' as the descriptor.
Image sources: EBSCO <http://web.ebscohost.com> 25.7.2013, ProQuest <http://search.proquest.com> 25.7.2013
In conjunction with search terms, or instead of them, different classification systems and codes can also be used to describe the contents of a document. Classification codes are often hierarchical and independent of language.
For example, the Abi/Inform database uses its own classification, in which the code 9520 refers to a small business. The code can be used as a search term.
Image source: ProQuest (ABI/Inform) <http://search.proquest.com> 1.7.2013
More about classification systems
The choice of search term is dependent on the database being used and its user interface; what information the database contains and what search strategies can be used.