. Author manuscript; available in PMC: 2014 May 1.

Published in final edited form as: Br J Math Stat Psychol. 2012 May 29;66(2):245–276. doi: 10.1111/j.2044-8317.2012.02050.x

Table 7.

Application to Empirical Data

	Unidimensional Model	Bifactor Model
number of free parameters, ν	90	103
−2 x log-likelihood	47374.5	44361.0
Akaike Information Criterion (AIC)	47554.5	44567.0
Bayesian Information Criterion (BIC)	47999.9	45076.7

test statistic based on full one- and two-way marginal tables (M₂)
M₂	8489.4	6541.6
degrees-of-freedom	2430	2417
p	0.0001	0.0001
RMSEA (90% Confidence Interval)	0.049 (0.048,0.050)	0.032 (0.031,0.034)

test statistic based on reduced one- and two-way marginal tables ( $M_{2}^{*}$ )
M₂	2131.8	199.3
degrees-of-freedom	81	68
p	0.0001	0.0001
RMSEA (90% Confidence Interval)	0.156 (0.150,0.162)	0.043 (0.036,0.050)