The Methods And Comparison Of Test Equating In Item Response Theory

The research on test equating is very important for test equity,item banking,teaching quality assessing,and computerized adaptive test. First,one main work of test equating is to estimate equating coefficients,In the paper in the light of Item Response Theory an abstract form is introduced,which makes all test equating methods in uniform,by the abstract form,the relationships among the existed methods being found out,and some new methods being derived,including Relative Entropy equating method and Logcontrast equating method. Second,the procedure of estimating test equating coefficients may be dull or complex,in this thesis,a uniform procedure,which not only improve the computing efficiency,but also is the base of comparison of various equating methods,is given. Third,because the comparison of equating methods is a major part on test equating research,there is not a reliable criterion up to now,in order to compare the new methods with the existing ones,in this thesis an objective approach is given. The new approach consists of three steps:1. making Monte Carlo simulation;2." computing Root Square Mean Deviation (RMSD) of outcome in Monte Carlo studies;3. using Wilcoxon signed ranks test to analyze RMSD. The results having been compared show that the new methods are as good as those existing ones,even better in some case in view of statistics.