Almost a year ago I wrote A Google Primer, which some of you have told me you have found useful. This week I took a careful look at Google Scholar, and I’ll pass on some of the things I discovered. Scholar’s advantages and disadvantages have been well documented and I won’t go into them in detail here. See also A little Google history from the Internet Archive
See Shultz M. Comparing test searches in PubMed and Google Scholar. J Med Libr Assoc 2007; 95(4):442-445. [Open Access]
Google Scholar is terrific for serendipitous searching, especially if you use the Cited By feature. This is what I tell my students:
- Use Google Scholar as a starting point, keeping in mind limitations such as lack of subject indexing and undeterminable coverage
- Use the Advanced Scholar Search to take advantage of several advanced search features at the same time, and use the Scholar Preferences
- Enrich your searches by using other (free) databases such as PubMed or TRIP (Turning Research Into Practice) or the Index to Chiropractic Literature because Scholar’s coverage of MEDLINE, for example, is incomplete (although Scholar does cover a lot of “grey literature” absent from PubMed)
If you compare the search features on the Google Advanced Search and Google Scholar Advanced Search pages, some puzzling differences appear. Some features may be used in both. Here are some highlights of Scholar and Google search features:
Downloading into bibliographic software
I have been frustrated by what I thought was the inability to download references from Scholar. Well, this week I discovered that you can download from Google Scholar, and into 5 different software managers. Outstanding! Simply go to Scholar Preferences , scroll down to Bibliography Manager and choose one. See the link Import into RefMan on the bottom line in this screen shot (click on the image to enlarge it):
Link to search (Turn on the bibliography manager in Google Scholar to see all the links.)
Boolean searchingWords and phrases in both Googles are automatically ANDed. OR can be used (uppercase). You can NOT words or phrases by using - .Truncation or wildcard searching
In Google, use * to capture all forms of a word, e.g. chiropract*. Oddly, this does not work in Google Scholar.
“Exact phrase” is an option in both advanced search screens; enter phrases in quotation marks in basic searches.
This is a search feature in Google Scholar advanced search; au: in basic search also works, although results may be incomplete (e.g. au: taylor-vaisey)
This is a search feature in Google Scholar advanced search. Caution: Titles are entered in the form in which they appear in publications, and the search screen only gives one chance to enter titles. Publication: seems to work in some cases, but is unreliable. There is no way to capture all forms of a title in one search, as far as I can see.
You can specify date ranges in Scholar; broad ranges only are available in Google.
Google has a long drop box for countries on its advanced search screen. You can also choose from many languages in Google preferences. Scholar has no language feature on its search page, but you can choose 8 language limiters in Scholar Preferences. (A puzzling difference that may have to do with bias …)
This is a choice on the Google advanced search page, not on Scholar. But you can limit by file type in Scholar basic search (e.g. filetype:pdf).
This is a feature on the Google advanced search page, not on Scholar. But you can limit by domain in Scholar basic search (e.g. site:edu).
The “Cited by” feature is only in Google Scholar (see above screen shot). Also use the Related Articles feature. I don’t know how they create the latter but they seem to pick title words and authors. I tried to figure out how to find all the “cited by” records for a particular author, but this seems to be pretty random, unlike PubMed, which uses a formula.
Google Scholar includes broad subject categories in its advanced search. In Google, however, I just discovered that you can refine a search on a topic like “chronic fatigue syndrome” by the categories below. (These appear only after you do a search.)
Treatment; Tests/diagnosis; For patients; From medical authorities; Symptoms; Causes/risk factors; For health professionals; Alternative medicine; Patient handouts; Clinical trials; Continuing education; Practice guidelines