Keywords and subject terms – the same or not?

When speaking about information retrieval, you have probably run into concepts like keywords, search terms, subject terms and subject headings.

When speaking about information retrieval, you have probably run into concepts like keywords, search terms, subject terms, subject headings, and so on. Some of these terms are also current in the final phase of your thesis process: students need keywords and subject terms when writing their abstracts and uploading their thesis to Theseus. Therefore, you should know some basic facts about them.

Keywords

What are they?

  • freely chosen words describing the content of the document

Where do you need them?

  • in your thesis abstract
  • as search terms in information retrieval

Where do you find them?

  • you can choose them yourself

 

Subject terms

What are they?

  • keywords that belong to an official controlled vocabulary like YSO (General Finnish Ontology)

Where do you need them?

  • as search terms in information retrieval
  • when saving your thesis to Theseus, you must use YSO subject terms on the upload form to describe your thesis content

Where do you find them?

Keywords

A keyword can be any word describing the content of a document (book, thesis, article, picture, video), and you can choose them yourself. When the reader glances through the document's keywords, they immediately know what the document mainly deals with. Usually, keywords include the document’s main topics like social media, marine industry, preschoolers, artificial intelligence, hip replacement. Keywords can also inform the reader which person, business or work the document is about (Usain Bolt, Microsoft, Bible) or which research method or technique has been used (literature review, survey, acrylic painting).

Subject terms

Some of the keywords might belong to a standardized vocabulary. They are called subject terms or subject headings. A collection of subject terms is often called thesaurus (pl. thesauri). The most widely used thesauri in SAMK are MeSH (www.ncbi.nlm.nih.gov) (Medical Subject Headings) and YSO (finto.fi) (General Finnish Ontology). In a thesaurus, one subject term has been chosen to represent each concept, as well as all its forms and synonyms. For example, in MeSH the term aged (www.ncbi.nlm.nih.gov) represents the words elderly, older people, older adults etc. A thesaurus also shows the term’s narrower terms, broader terms, and other related terms.  This feature makes it a useful tool when looking for good search terms for information retrieval. Finnish thesauri collected in Finto.fi service also suggest translations for the term in Finnish and Swedish (see FinMeSH (finto.fi).

Subject terms are used to describe the content of a document when it is saved to a database. For example, the books in SAMK Finna have their own subject terms, usually selected by a cataloging librarian. You can see the subject terms by clicking on "SHOW ALL DETAILS" (samk.finna.fi) in the book details. These subject terms are usually taken from YSO (Finnish) or LCSH (id.loc.gov) (English, Library of Congress Subject Headings). Similarly, theses uploaded to Theseus have their own subject terms taken from YSO. These are taken by the author of the thesis during the upload process. Students get a little help from artificial intelligence here, though. Try giving a snippet of text (for example, your thesis abstract) to ai.finto.fi and see which subject terms it suggests.

Because the subject terms describing the content of documents are saved to literature databases, they tend to work efficiently in information retrieval. However, subject terms do not contain all the concepts in the world. Therefore, you should also use other keywords in your searches – they usually yield useful additional results.