CTTsub                  This main function estimates true subscores
                        using different methods based on original CTT
                        scores.
Yen.OPI                 Estimating true subscores using Yen's OPI
data.prep               This function prepares data into a requried
                        list format
scored.data             Sample scored data
subscore.Wainer         Estimating true subscores using Wainer's
                        augmentation method
subscore.s              Computing subscores using Haberman's method
                        based on observed subscores.
subscore.sx             Computing subscores using Haberman's method
                        based on both observed total scores and
                        observed subscores.
subscore.x              Computing subscores using Haberman's method
                        based on observed total scores.
test.data               A list of objects that include both test
                        information and subscores.
