Table 5.

Descriptive statistics for ability by year

Year	Type of class		Mean	SD	Minimum	Maximum
Year 1	CP and Collab (n = 178)	Pre	− .701	.610	− 2.58	.81
		Post	− .526	.644	− 2.19	1.08
	Gifted and honors (n = 229)	Pre	− .005	.592	− 1.61	1.29
		Post	.383	.603	− 1.87	1.62
Year 2	CP and Collab (n = 141)	Pre	− .534	.563	− 2.22	1.00
		Post	− .083	.564	− 1.65	1.47
	Gifted and honors (n = 252)	Pre	.123	.530	− 1.68	1.62
		Post	.761	.578	− 0.68	2.41
Year 3	CP and Collab (n = 134)	Pre	− .507	.503	− 1.65	1.04
		Post	.030	.654	− 1.66	1.72
	Gifted and honors (n = 344)	Pre	.055	.599	− 1.92	1.58
		Post	1.175	.805	− 1.06	3.33