An evaluation of computerized adaptive testing for general psychological distress: combining GHQ-12 and Affectometer-2 in an item bank for public mental health research

Table 5 Root mean square errors (RMSE) between CAT estimated θs and true θs

Theta estimator	Item selection	Prior	SEM threshold θ_true ~ N(0,1)					SEM threshold θ_true ~ U(-3,3)
Theta estimator	Item selection	Prior	0.25	0.32	0.40	0.45	0.50	0.25	0.32	0.40	0.45	0.50
MLE	UW-FI	-	0.253	0.318	0.401	0.449	0.489	0.266	0.322	0.402	0.457	0.499
MLE	FP-KL	-	0.253	0.319	0.401	0.448	0.488	0.266	0.324	0.402	0.457	0.497
BME	UW-FI	Normal	0.251	0.322	0.407	0.453	0.476	0.279	0.355	0.48	0.558	0.619
BME	UW-FI	Uniform	0.257	0.318	0.401	0.447	0.491	0.266	0.318	0.401	0.451	0.502
BME	FP-KL	Normal	0.251	0.322	0.406	0.448	0.474	0.279	0.355	0.48	0.555	0.619
BME	FP-KL	Uniform	0.259	0.318	0.395	0.44	0.484	0.263	0.322	0.396	0.452	0.491
EAP	UW-FI	Normal	0.247	0.313	0.383	0.429	0.465	0.276	0.345	0.448	0.516	0.575
EAP	UW-FI	Uniform	0.253	0.315	0.383	0.422	0.462	0.261	0.319	0.39	0.43	0.466
EAP	FP-KL	Normal	0.247	0.313	0.383	0.427	0.468	0.276	0.346	0.447	0.512	0.585
EAP	FP-KL	Uniform	0.253	0.315	0.377	0.422	0.463	0.263	0.319	0.385	0.43	0.465

ISSN: 1471-2288