Some aspects of the "impact factor", a quantitative measure of journals' influence on journals in scientific fields, were discussed in the preceding issue of the Croatian Medical Journal by Dr Eugene Garfield, one of its devisers. This factor can be of interest to authors, journal editors, and policy makers, but they should keep in mind the complexity of the determinants of impact factors while using them in coming to their particular kinds of decisions. A clearer picture of the influence a journal may have in its own scientific field rather than among all scientific journals could come from a variant of the impact factor, "the scope-adjusted impact factor". The calculation of this variant impact factor is described. A table presents some sample data from this calculation and shows how the relative positions of some major journals shift when they are ranked by this factor rather than the unadjusted impact factor. The possible value of this variant factor may merit further testing.