This week's BMJ editorial discusses impact factors and their abuse, and there are some rapid responses as well.
Note also the House of Commons Science and Technology Committee's discussion of impact factors as a part of their report on scientific journals and more recently in their report on the RAE , in which they say: "It is not acceptable for peer review panels to rely on the place of publication as a guarantee of quality. We recommend that HEFCE to instruct panels to desist from this practice for RAE 2008 and ensure that panels are sufficiently large and well staffed to make informed judgements of the quality of the submissions."

