Half-lives, policies and embargoes | Scholarly Communications @ Duke

"Over the holidays I was contacted by a writer for Library Journal asking me what I thought about a study by Phil Davis, which was commissioned and released by the Association of American Publishers, that analyzed the 'article half-life' for journals in a variety of disciplines and reported on the wide variation in that metric.  The main finding is that this idea of half-life — the point at which an article has received half of its lifetime downloads — varies a great deal from discipline to discipline. The writer asked me what I thought about the study, and about a blog post on the Scholarly Kitchen in which David Crotty argues that this study shows that the experience of the NIH with article embargoes — that public access after a one-year embargo does not harm journal subscription — cannot be generalized because the different disciplines vary so much.  I sent some comments, and the article in LJ came out early last week. Since this exchange I have learned that the Davis study is being presented to legislators to prove the point Crotty makes — that public access policies should have long embargoes on them to protect journal subscriptions.  It is worth noting that Davis does not actually make that claim, but his study is being used to support that argument in the on-going debate over implementing the White House public access directive.  That makes it more important, in my opinion, to be clear about what this study really does tell us and to recognize a bad argument when we see it. Here is my original reply to the LJ writer, which is based on the fact that this metric, 'article half-life,' is entirely new to me and its relevance is completely unproved.  It certainly does not, in my opinion, support the much different claim that short embargoes on public access will lead to journal subscription cancellations ..."