The Jansen and Roskam (1986) approach to joining categories of graded responses presents valid arguments that are subject to empirical test. The multiplicative Poisson (MPM) model of D. Andrich can be seen as an approximation to the continuous response model of Muller (1987). An extension of the MPM is suggested. (SLD)

These further remarks on the nondichotomization of graded responses attempt to clarify the differences in perspective between the two previous articles. The special case of the multiplicative Poisson model reveals why the joining assumption and dichotomization are not, in general, properties of the unidimensional Rasch model. (SLD)

SOLAS is a general-purpose program for univariate statistical analysis with the ability to perform multiple imputation (MI) for dealing with missing data. Several completed data sets can be obtained and analyzed separately, and results can be combined so that extra variability due to missing data is taken into account. (SLD)

Presents a review of microcomputer-based software packages that have been designed for Operations Research, Management Science, and Production and Operations Management. Listed for each package are price for student use, minimum system requirements needed to run the package, and maximum capability constraints. (PK)