For two tests measuring the same trait, the program, BIV20, equates the scores using the two True score distributions estimated by the univariate method 20 program (see Wingersky, Lees, Lennon, and Lord, 1969) and, with these equated true scores and their distributions, estimates the bivariate distribution scores and the relative efficiency of the…

Procedures are presented for equating simultaneously several tests which have been calibrated by the Rasch Model. Three multiple test equating designs are described. A Full Matrix Design equates each test to all others. A Chain Design links tests sequentially. A Vector Design equates one test to each of the other tests. For each design, the Rasch…

PRIME is a library of 44 batch-oriented computer routines: 20 major package programs, which use 12 statistical utility routines, and 12 other utility routines for input/output and data manipulation. This manual contains a general description of data preparation and coding, standard control cards, input deck arrangement, standard options, and…

The Rasch model for test analysis is described and compared with two-parameter and three-parameter latent-trait models. Conditional maximum likelihood equations for estimating item parameters are derived, and estimates of person parameters are described together with their confidence intervals. Goodness of fit tests are discussed, including a…