The effectiveness of alternative procedures to correct for rater leniency/stringency effects was studied when true scores were known. Ordinary least squares, weighted least squares, and imputation of the missing data consistently outperformed averaging the observed ratings; and the imputation technique was superior to the least squares methods.…

The validity of the assumptions under which the ordinal true score test theory was derived was examined using (1) simulation based on classical test theory; (2) a long empirical test with data from 321 sixth graders; and (3) an extensive simulation with 480 datasets based on the 3-parameter model. (SLD)