. Author manuscript; available in PMC: 2015 Jun 1.

Published in final edited form as: J Exp Psychol Gen. 2013 Nov 11;143(3):1026–1048. doi: 10.1037/a0034847

Table 3.

Measurement invariance results for the five ability constructs in three age groups

	df	Age 18–39			Age 40–64			Age 65–99
	df	Χ²	CFI	RMSEA	Χ²	CFI	RMSEA	Χ²	CFI	RMSEA
Memory
Model 1	19	33	.994	.024	32	.998	.017	39	.993	.030
Model 2	23	38	.994	.022	39	.997	.017	41	.994	.026
Model 3	27	59	.987	.030	52	.996	.020	69	.985	.037
Model 4	33	67	.986	.028	60	.995	.019	82	.982	.036
Speed
Model 1	19	73	.978	.047	38	.997	.021	67	.987	.047
Model 2	23	96	.970	.049	45	.997	.020	80	.985	.046
Model 3	27	102	.969	.046	89	.990	.031	106	.979	.050
Model 4	33	117	.965	.044	106	.989	.031	119	.977	.047
Vocabulary
Model 1	43	140	.986	.042	243	.988	.045	178	.974	.052
Model 2	49	158	.985	.041	259	.988	.043	181	.975	.048
Model 3	55	268	.970	.054	296	.986	.043	209	.970	.049
Model 4	63	288	.968	.052	310	.965	.041	270	.960	.053
Reasoning
Model 1	19	41	.993	.030	30	.999	.016	22	.999	.011
Model 2	23	60	.988	.035	38	.998	.016	25	.999	.008
Model 3	27	93	.979	.043	80	.993	.029	27	1.00	.002
Model 4	33	102	.978	.040	93	.992	.028	38	.998	.012
Space
Model 1	19	48	.993	.034	80	.992	.037	18	1.00	.000
Model 2	23	56	.992	.033	85	.992	.034	19	1.00	.000
Model 3	27	128	.975	.053	147	.984	.044	28	1.00	.005
Model 4	33	133	.975	.048	150	.984	.039	30	1.00	.000

Note: df is degrees of freedom, CFI is Comparative Fit Index, and RMSEA is Root Mean Squared Error of Approximation. CFI values greater than about .90 and RMSEA values less than about .08 are often considered to reflect a reasonably good fit (Kline, 2005). Model 1 is configural invariance, Model 2 is weak factor invariance (equal factor loadings), Model 3 is strong factor invariance (equal intercepts), and Model 4 is strict factor invariance (equal unique variances).