Conditional Maximum Likelihood Estimation in Polytomous Rasch Models Using SAS

Figure 1

Item characteristic curves (ICCs) for HADS item 9 plotted with option ICC=YES. The curves intersect at the thresholds 𝛽₉₁=−0.93, 𝛽₉₂=1.51, and 𝛽₉₃=2.43.