Open access and impact factor

["Rick Anderson" <rickand@unr.edu>]

Every time someone uses "enhanced impact factor" as an argument for open
access, a tiny little bell goes off in the back of my head, and this
morning I finally figured out why.  Stop me if this is a naive question or
if I'm fundamentally misunderstanding the argument, but it seems to me
that the purpose of impact factor data is to measure the importance of one
article relative to others.  If the article's impact factor is enhanced by
its free availability to the public (rather than by its intrinsic merits
or its impact on the thinking and research of others), then isn't open
access simply making the impact-factor data less meaningful?

In other words, given two articles of equal merit and potential influence,
one of which is freely available to the public and the other of which is
only available to those who pay, wouldn't we expect that the impact of the
former would be higher than that of the latter?  And if so, how is the
difference between those two impact factors meaningful or useful?

-------------
Rick Anderson
Director of Resource Acquisition
University of Nevada, Reno Libraries
(775) 784-6500 x273
rickand@unr.edu