Table 3. Cumulative Frequency Distributions of Difference Scores of Theta.

	Mixture CAT using LVMM parameters	Conventional IRT model (all items)	Conventional CAT
Relative cumulative frequency (%)	Difference score (A: B)	Difference score (A: C)	Difference score (A: D)
Minimum	-0.23
5	-0.12	-0.52	-0.43
10	-0.07	-0.44	-0.37
25	-0.03	-0.27	-0.23
50	0.01	-0.06	-0.01
75	0.04	0.32	0.26
90	0.07	0.48	0.40
95	0.09	0.50	0.42
Maximum	0.16

Notes. The difference scores are calculated by subtracting the model predicted PRO scores from the referent PRO scores.