. Author manuscript; available in PMC: 2026 Apr 1.

Published before final editing as: J R Stat Soc Ser A Stat Soc. 2025 Apr 1:10.1093/jrsssa/qnaf033. doi: 10.1093/jrsssa/qnaf033

Table 4.

Fit of exploratory unidimensional latent class IRT models by the number of classes. Eight binary quality indicators.

No. of classes	Estimated Log likelihood	No. of parms.	AIC	BIC

1	−69, 209.50	8	138,435.0	138,499.7
2	−66, 828.08	17	133,690.4	133,827.9
3	−65, 675.85	19	131,389.7	131,543.3
4	−65, 673.74	21	131,389.5	131,559.3
5	−65, 675.66	23	131,397.3	131,583.3

Bolded entries designate best model.