Sorry to return to this boring topic again; but here is an excellent example of both what is wrong with judging research by citations, and a challenge to those who would do so.
From New Scientist, 6 February 2010:
[X's] 2004 paper in Science has now been cited over 350 times by other researchers. Yet many remain sceptical. One criticism is that …
How does the journalist know this? Because the criticism is expressed in journal articles, which can be found because they cite the paper concerned. Not all citations are positive!
So, a small challenge: look at the 350 papers citing this work; how many of them are critical? If critical citations count as –1, what figure do we get?
Incidentally, two articles later in New Scientist we read:
One leading expert, on condition of anonymity, told New Scientist that the estimates were “ridiculous” and privately accused [Y] of being “more interested in getting papers into Nature and Science than in getting it right”.
Leaving aside the scurrilous personal attack under this cloak of anonymity, is there a mechanism that could explain this paradox? I think there is. Just as researchers are under pressure to publish in high-impact journals, so journals must be under pressure to publish articles that will attract more citations. A controversial article will do so, despite having a higher probability of being wrong; indeed, all the better if it inspires many researchers to refute it!
It may appear that I am saying that we shouldn’t write speculative papers. Of course I am not; merely that citation data does not reliably judge the worth of a paper without further information, which can only be obtained by reading the paper and making a judgment.
But, to close: Mathematics notoriously has lower citation rates than most of science. Probably the main reason for this is that, if I quote a theorem, I only need to cite the proof of the theorem, not to pile up experimental evidence for it. But perhaps another reason is that mathematics is relatively uncontroversial (a proof is a proof, after all), and mathematics papers don’t tend to attract negative citations.