Advanced Search Techniques
An advanced search involves using a combination of Controlled Vocabulary and Subject Heading terms and free text/keyword searching.
Controlled Vocabulary/Subject Heading searching involves searching for studies categorized under a given subject. Each study within a (relevant) database is categorized, according to the topic(s) it covers, these categorizations are it's Subject Heading terms. An article about learning support in Universities, for example, would likely be given the Subject Headings 'Learning Support' or 'Student Support' and 'Universities' as these are the main areas which the article focuses on.
A Controlled Vocabulary/Subject Heading search is more precise than a free text/keyword search as it will retrieve results where the main focus of the study relates to the Subject terms that you entered. A free text/keyword search will retrieve results where your search terms are mentioned but the results may not focus on those terms.