Whats the difference between subject and keyword searching in MEDLINE?
Most MEDLINE search engines allow you to search both by Medical Subject Headings, the controlled vocabulary, and by “keyword,” usually meaning words in the title, abstract or subject headings. Subject searching is more precise and will usually result in a narrower search and fewer hits, while keyword searching means a broader search and more hits. In most cases, subject searching with Medical Subject Headings provides the most satisfactory results. However, though keyword searching can result in a huge set of articles in which many miss the mark, using keywords may be necessary, or even preferable, when there is no good Medical Subject Headings term available. This is often the case with new or unusual concepts or terms.
