Philip Ball writes about the Hirsch h- index which is in fashion currently to predict the productivity and impact of researchers. in a nutshell, a scientist who has a h-index of X is one who has published X papers with at least X citations each. One has to say that the h-index does look better than some other indices, trying to encompass both quality and quantity. On the other hand, it does leave out some prominent names.
For me, the h is like the Nobel Prize; those who have a high one are almost without exception really good, but there are so many who are not in the top twenty who are also noteworthy. For example, what about Oliver Lowry, who is the most highly cited researcher ever, for his discovery of the folin phenol reagent in biochemistry? Or what about Canadian Axel Becke, whose paper on improved density functionals is one of the most highly cited papers ever, and the most highly cited one in the last twenty years (I believe). Also consider the fact that his functional, instantly recognisable to theoretical and other chemists in "B3YLP" (Becke-Yang-Lee-Parr) is ubiquitous in structure calculations in every branch of chemistry.
The problem with the h-index of course is that it does not recognise flashes of brilliance or contribution which have become ubiquitously used in the field. Just like many other indices of recognition, it leaves aside discoveries which in terms of utility are very important, but which in terms of novelty may not be regarded as stellar. Maybe their originators won't get Nobel prizes, but in some ways their contributions are equally "important". What about Charles Pederson who discovered crown ethers (although he did get a Nobel)?
However, in the end, the h-index like any other index fails, because it aims to be a quantitative indicator of "greatness" or "importance", and at least in people's minds, tries to say which scientist is more or less important or greater. Some scientists like E J Corey are obviously important or great. But others like the ones above are also pretty important, but this is not captured in the h-index.
Nonetheless, I think the index is probably the most reasonable citation system that has come out in many years.
2016 Nobel Prize predictions
10 hours ago in The Curious Wavefunction