Thanks to Bee of BackReaction, I have become aware of a new feature of Google Scholar, called Google Scholar Citations. It is essentially a free alternative to Web of Science (WoS), allowing researchers to create a public profile, with a list of all of their publications, including the citations garnered by each article.
(This is mine, by the way).
Below is an excerpt from the post on Google Scholar’s Blog, announcing this new service:
“… you can quickly identify which articles are yours, by selecting one or more groups of articles that are computed statistically [...] we collect citations to your articles, graph them over time, and compute your citation metrics – the widely used h-index; the i-10 index, which is simply the number of articles with at least ten citations; and, of course, the total number of citations to your articles…”
I am sure that not everything that Google does is good, but I cannot imagine this new service not being welcomed by the vast majority (totality ?) of researchers. The notion of having to log into a secure site and pay money (indirectly through my institution) to access information that is really meant to be public, such as number of articles published by scientists and their citations, seems to me to be another vestige of a time past — like scientific journals printed on paper. Granted, it is clearly a way to suck more people into using Google services (one starts with Google Scholar, then tries out Google Apps, then Mail… but I guess it is called market strategy). Still, I like the concept and applaud the effort. I think that the scientific community badly needed something like this, and I hope that this tool becomes widely adopted soon.
The implementation may require some fine tuning, but, hey, we are patient, are we not ?
The one thing that I have noticed (obviously it is also discussed in the BackReaction post mentioned above, as well as here), is that the computed h-index differs from that yielded by WoS . I have not carried out a scientific analysis, I am sure some
nerd scholar will go through this exercise soon, but my “gut feeling” is that the difference should be typically of the order of 10-15%. Thus, I am not sure whether this is going to be a huge issue in the end, because numerical measures such as the h-index (of which I am a big fan), should be taken with a grain of salt. That means that an “error bar” should be almost automatically ascribed to any value of h, and I think 10-15% is probably a good rule of thumb anyway.
I have not (yet) read any attempt to explain where the difference between the h-index computed by Google Scholar and WoS may originate. Off the top of my head, I can think of one reason why Google Scholar ought typically output a greater number. If one searches on Google Scholar how many times one’s article is cited, Google Scholar lists all cites found anywhere on the Web, including citations to that article made on unpublished material, such as doctoral theses, as well as articles published in preprint form, typically uploaded to the ArXiv repository.
Now, my position on citations is expounded in this old blog post of mine: A citation is a citation is a citation — in the sense that it does not really matter who cites the article (including the author herself), nor where the citation occurs (for example, citations made in preprints or theses are fair game, in my view). However, one should be careful not to count the same citation more than once, and with Google Scholar that is a bit tricky. For, a citation to a given article made in a preprint, is counted separately from the same citation made in the subsequently published article arising from said preprint, i.e., the same citation is counted twice.
It seems to me that this should be easily fixable — and like I stated above, I doubt if a difference of this magnitude is even worth getting all worked up over .
Other issues ? Well, I have been doing some reading (mostly on blogs) over the past few hours, regarding problems with finding individual researchers on Google Scholars based on their last names. I think that the most obvious present limitation, is that they have to have Google accounts, but I am thinking that this will not be an issue for long (the whole world is getting Google accounts soon… right ?). In terms of differentiating individuals with the same last name, my case is similar to Bee’s, in that my last name is fairly uncommon, so, finding myself was a piece of cake. Obviously, in general it is far from trivial, but I do not think that it is any easier in WoS.
 In my case, Google Scholar gives 28, whereas WoS 25, the reason being that I have a bunch of papers cited 25 times which have already been cited a few more times in yet unpublished ArXiv preprints. Google Scholar counts those, WoS does not. I expect those preprints to become eventually published work, at which point WoS will add those citations. Problem is, and Google Scholar will add them too… again (see above).
 There — so much for “I shall never end sentences with prepositions !”…