Interesting article in today’s Wall Street Journal:  Science Journals Artfully Try To Boost Their Rankings, by Sharon Begley:

Just as television shows have Nielsen ratings and colleges have the U.S. News rankings, science journals have impact factors. Now there is mounting concern that attempts to manipulate impact factors are harming scientific research.

Conceived 40 years ago, impact factors are essentially a grading system of how important the papers a journal publishes are. "Importance" is measured by how many other papers cite it, indicating that the discoveries, methodologies or insights it describes are advancing science….

The result, says Martin Frank, executive director of the American Physiological Society, which publishes 14 journals, is that "we have become whores to the impact factor."…

Journals can manipulate impact factors with legitimate editorial decisions. One strategy is to publish many review articles….Reviews don’t report new results but instead summarize recent findings in a field. Since it is easier for scientists to cite one review than the dozens of studies that it summarizes, reviews get a lot of citations, raising a journal’s impact score….

One questionable tactic is to ask authors to cite papers the journal already has published….

Journals also can resort to [self-citation and] …. can limit citations to papers published by competitors, keeping the rivals’ impact factors down….

Scientists and publishers worry that the cult of the impact factor is skewing the direction of research. One concern, says Mary Ann Liebert, president and chief executive of her publishing company, is that scientists may jump on research bandwagons….

In our recent article, we discuss the limitations of the impact factors used to rank law schools and law faculty.  Ranking Law Schools: Using SSRN to Measure Scholarly Performance, 81 Ind. L.J. 83, 92-95 (2006).  Our Leiter’s Law School Rankings web site contains several studies on the scholarly impact of law faculty.