A question that often arises is “How useful is a free text search in PubMed?” Free text searching is fine for some searching purposes but does not take full advantage of PubMed’s features. I experimented by comparing a free text search with a search using Boolean operators for the topic “heparin induced thrombocytopenia”. The results?
You can find out exactly how the search was done by clicking the details tab which, in the case of our searches, reveals the exact same strategy for both:
(No other popular medical search engine that I know of allows you to do this, by the way).
These strategies, however, yield 2908 hits. This illustrates the disadvantage of free text searching which is that it usually produces an unmanageable number of citations. A more restrictive search strategy is often needed. One method is to restrict search terms to the title field. Without the title restriction PubMed searches throughout the entire citation including the abstract. The results will include many articles in which heparin induced thrombocytopenia is incidental to the main topic---articles you probably don’t want. By applying the title restriction you confine your results to articles that have all three words in the title. Type [ti] after each search term: