Subject analysis involves determining what an item is about conceptually and translating that analysis into subject headings from a controlled vocabulary. Key aspects of subject analysis include:
1) Objectively analyzing the content of an item by examining elements like the title, table of contents, and illustrations to identify topics, names, time periods, and other concepts.
2) Distinguishing between the subject of an item (what it is about) and its form or genre.
3) Translating identified keywords and concepts into the preferred terms from a controlled vocabulary to allow for multiple access points and relationships between terms. Controlled vocabularies help compensate for complexity in language.