Fig. 4

Average MSE of validity coefficient \( \gamma \) for six items and highly biased experts. Mean squared error (MSE) for validity coefficient \( \gamma \) using OBID (solid blue line) and ordinal CFA (dashed red line) when P = 6 (number of items) and experts are highly biased {\( {\rho}_0=\left(0.65,\;0.75,\;0.85,\;0.85,\;0.65,\;0.75\right)\Big\} \). The participant sample sizes are N = 50, 100, 200, and 500. The numbers of response categories are C = 2, 5, and 7, and the numbers of experts are K = 2, 3, 6, and 16. Note. OBID = Ordinal Bayesian Instrument Development; CFA = Confirmatory Factor Analysis