I've been looking some more at Gregory Sisk et al.'s "Scholarly Impact of Law School Faculties: Extending the Leiter Rankings to the Top 70." One of the things that I'm interested in is the methodology--taken from Brian Leiter's previous study of the top 25 faculties--that creates a weighted score by multiplying the mean citations of the tenured faculty over the past five years by 2 and then adding the median. Sisk's table 2 lists the mean and median for each of 70 schools, as well as the weighted score and rank for the weighted score (that Sisk et al. adjusted downward slightly to make it comparable to Leiter's earlier study, because they ran their citation study a few months after Leiter).
I've re-ranked the schools based just on mean and just on median (pdf of the ranking available here). My initial thought was that the median ranking might be the best snapshot of a faculty overall, because it's not susceptible in the way the mean is to one or a few highly cited faculty. Brian Leiter made this point about Erwin Chemerinsky at UC-Irvine here (fourth paragraph down).
What's interesting about this is that some of the schools that are already performing above their US News peer assessment rank do even better on the median ranking than the Sisk overall ranking -- take Florida State, which is ranked 19 in median citations to tenured faculty over the past five years. The University of Missouri also improves, for instance, from 55 overall to 43.
Previous coverage of the Sisk study at the faculty lounge has focused on the correlations between Sisk's weighted scores and other attributes of the schools -- like student credentials and bar pass rate -- and the relationship between Sisk's weighted scores and the citations to schools' main law journals. Since Brian Leiter posted on the study on Monday this has sparked a lot of commentary, including at ELS blog and Bainbridge.
Update: In response to Brian's comment about the problems with use of median, here's the list of the schools ranked by weighted score, mean, and median, with a final column that lists the difference between mean rank and median rank. The schools with a positive score had a higher median rank (they performed less well) than mean rank. While many schools had similar ranks for mean and median, there are a few that performed much better on median (like Washington University, Indiana Bloomington, Missouri, and Boston College) than mean; while some others performed much better on mean (Hawaii, Illinois, San Diego) than median -- which I take it suggests that they have some particularly highly cited faculty.