Impact factors

A feature article in this week's BMJ - How impact factors changed medical publishing—and science - examines the history, uses and abuses of the journal impact factor (IF). There are a number of quotes from Eugene Garfield, the creator of the IF, who notes that whilst IFs do have some value

It is the mindless use of citation data and impact factors that gets people
upset

A number of editorials and associated articles in the same issue argue the cases for and against impact factors.

Arguing against them, Gareth Williams' points out that

It is patently absurd to believe that the intrinsic value of a piece of research
is increased just because the editor of a "good" journal takes a shine to it.

Arguing in their favour, Richard Hobbs suggests

rather than just discarding impact factors we should consider solutions to the
problems.