Table 3. CFA fit indicators for PIP with 42 items (original) and our brief version of 12 items.

Model	S-B-χ2 a	Df b	p	S-B χ2/df c	CFI d	IFI e	RMSEA f
PIP Frequency-42 items	1575.4188	813	< .000	1.93	.66	.69	.06 (.058-.068)
PIP Difficulty-42 items	1502.3941	813	< .000	1.85	.76	.77	.06 (.055-.065)
PIP Frequency-12 items	88.393	48	< .01	1.84	.95	.95	.05 (.033-.074)
PIP Difficulty-12 items	72.002	48	< .01	1.50	.97	.97	.04 (.011-.063)

^a Satorra-Bentler scaled chi-squared.

^b Degrees of freedom.

^c Ratio between χ² & Df.

^dComparative fit index.

^e Bollet’s fit index.

^f Root mean-square error of approximation and 90% confidence interval of RMSEA.