Table 2.

Results of analyses of variance on T21-T11 change in composite scores as a function of age decade and number of test versions at T1

	Decade		Number T1 Versions		Decade X Num. T1 Versions
	F	pη2	F	pη2	F	pη2
Memory	11.81*	.046	16.24*	.013	1.01	.004
df	5,1233		1,1233		5,1233
Speed	5.99*	.020	48.86*	.032	0.52	.002
df	5, 1464		1,1464		5, 1464
Reasoning	2.30	.011	0.39	.000	1.91	.009
df	5,1073		1,1073		5,1073
Spatial Visualization	11.53*	.042	33.67*	.025	0.39	.001
df	5, 1325		1,1325		5,1325
Vocabulary	12.15*	.041	0.03	.000	1.51	.005
df	5,1431		1,1431		5,1431

Note:

^*p<.01. The degrees of freedom (df) differed across abilities because not all participants performed every test. Covariates in the analyses were self-rated health, word recall scaled score, and T1-T2 interval. Effect size is represented by partial eta squared (pη²) values.