It seems that I’m becoming an expert in search problems and bugs.
Partly because I search a lot, but also because my colleagues and I often share our search problems.
This time, while giving a class, Hanny and Heleen noticed that (a) combining two terms in the Cochrane Library Search Bar with ‘and’ gives less hits than when you (b) search for those terms individually and combine them in the History with ‘and’ (see Figures). This is odd, because it should not make any difference whether you look these words up individually (which takes more time) or combine them directly. The field in which both these terms should occur is in the title, abstract and/or keyword field.
(c) Searching via advanced search has the same effect as searching the terms separately in the search bar (#7, #9)
Two examples are given below: (1) obesity and sibutramine (sets #1-#9) and (2) sibutramine and body weight (#10-#14).
Both obesity and body weight are MeSH (key words from MEDLINE).
It is unclear why certain records can’t be found when combining them in the search bar. The order doesn’t matter, for instance. It might have something to do with certain keywords not being found when the keyword command is not directly next to term sought (set #12 in Search History, and figure below).
Anyway this is highly undesirable. Especially for the beginner, who just wants to find a cochrane systematic review by doing a quick search. Hopefully this ‘bug’ will be fixed soon, because important papers might be missed (see below).