ConstructMap is a graphical, menu-driven software package that combines a multidimensional IRT engine for estimating item and person parameters with tools for managing cross-sectional and longitudinal student response data and interpreting findings from such data. Graphical maps and reports are designed for use in settings in which progress on multiple measures can be examined and analyzed. Users can select expected a posteriori (EAP), maximum likelihood, or plausible value estimates of multivariate proficiency estimates. ConstructMap accepts dichotomous, rating scale, or partial credit items in between-item (each response is an indicator of a single dimension) or within-item (a response may be an indicator of multiple dimensions) multidimensional models.
ConstructMap produces Wright maps that align person estimates with item estimates on a logit scale, and item characteristic and cumulative probability curves. It estimates item parameters using marginal maximum likelihood techniques. Integrals are approximated using quadrature or Monte Carlo methods, with user-defined number of nodes and upper and lower bounds of the latent traits. Users may also define convergence criteria and iteration limits. Differential item functioning and item bias can be explored by partitioning the response data on user-defined grouping criteria. Traditional item-analysis statistics are produced by ConstructMap as well as item response modeling fit statistics.