Subject headings and keywords describe the contents of the document making information retrieval easier by allowing searching the database by subject. It should be noted that a keyword is freely chosen word describing the contents of the thesis, while a subject heading is a word that has been accepted into a standardised index of subject headings.
The General Finnish Ontology (YSO) covering all fields of science and information is widely used by Finnish universities. Words taken from an index of subject headings, such as YSO, usually yield better search results, because the same controlled vocabulary is used in other documents to describe the same concept. In addition to common nouns, subject headings and keywords may include proper nouns such as names of persons, communities, geographical locations, works, and art movements.
Choose 6–12 words, of which at least some should be YSO subject headings, to characterise the essential contents of your thesis. While the minimum requirement is assigning headings in the language of the thesis, a larger number of subject headings in more than one language (English/Finnish/Swedish) increases the findability of your thesis. Use clear language in your thesis as well as in its subject headings and keywords.
You can access the YSO ontology at
YSO is a trilingual (Finnish/Swedish/English) vocabulary where the terms are organised into a hierarchy.
To search for a word, type it in the search field in the user interface. Even when the word is not an acceptable subject heading, YSO will help you find one, as it has a wide range of entry terms, which lead you to the concept you are searching for and provide a reference to the appropriate subject heading.
If you get no search results, try another word with the same meaning.
Type e-services in the search field.
Although this will give you a search result in the YSO, e-services is not a subject heading in the vocabulary, but listed as an entry term, which leads you to the appropriate subject heading, electronic services. In addition, sähköiset palvelut (Finnish) and elektroniska tjänster (Swedish) are listed as appropriate subject headings.
When you click on electronic services, you see more options: broader, narrower or related concepts that you could also use as subject headings.
(See images below.)
Alternatively, you can browse subject headings as an alphabetical or hierarchical list in the left-hand column (image).