Citations versus limitations of citations: beyond Hirsch index

It appears popular, particularly among science administrators, to use citations and various citation measures for ranking scientists, as if such exercises would reflect the scientific potential of the persons considered. In recent time the Hirsch index h in particular has obtained visibility in this respect in view of its simplicity. We consider a possible extension of the concept of selective citations, which in fact is innate to the h index, and propose a simple generalization, indices H and Q, which to a degree supplement the information accompanying the evaluation of h. The H index keeps record of the "history" of citations and the quotient Q = H/h is a measure for the quality of a scientist based on the history of his/her citations.