These are the ranking model changes that were used in the faculty resources part of the rankings:
1. Student faculty ratio was changed to a doctoral student-faculty ratio for full-time equivalent doctoral students to full-time faculty from a full-time degree seeking doctoral and master's degree student ratio to full-time faculty. In the ranking model a lower ratio being more favorable. The variable's weight in the ranking model was increased to 4.5 percent from 2.0 percent.
2. The number of doctoral degrees granted was changed to a ratio of doctoral degrees in 2006-2007 to full-time faculty members using the total number of doctoral degrees granted in 2006-2007. A lower ratio is better than a higher ratio. The variable's ranking model weight remained unchanged.
3. The proportion of fall 2007 degree-seeking students that were doctoral students was dropped from the ranking model.
These are ranking model changes that were used in the research activity resources part of the rankings:
1. The proportion of full-time faculty engaged in funded research was dropped from the ranking model.
2. The weight in the ranking model of the average research expenditures per full-time tenured and tenure-track faculty member averaged over fiscal years 2006 and 2007 was increased to 15 percent from 10 percent.
Corrected on 9/18/2008: A previous version of this article incorrectly explained the "doctoral degrees granted" measure.