Table 1. Results of nonparametric comparisons of all university tier groups.

				Wilcoxon Rank Sum / Mann-Whitney U		Kolmorov-Smirnov
	Rank pairing	n1	n2	U	p	D	p
Individual groups	1–10 vs. 11–20	607	532	3.641e5	< .001*	0.134	< .001*
	1–10 vs. 21–100	607	732	4.368e5	< .001*	0.156	< .001*
	11–20 vs. 21–100	532	732	3.420e5	.319	0.054	.318
Merged groups	Higher (1–10) vs. Lower (>10)	607	1264	6.163e5	< .001*	0.146	< .001*

All individual groups’ pairwise comparisons are significant (denoted with *) except for rank 11–20 vs. 21–100 (top three rows). We therefore collapsed across the two similar lower groups to create a single pair of groups (bottom row). This pair of groups—Higher vs. Lower tier—was used in all further analyses.