NORC has a long history in the development and application of psychometric methods and staff are experienced in the design and implementation of large-scale studies with assessment components. In addition, staff in our Statistics and Methodology Department have developed and applied item response theoretical (IRT) methods to educational, vocational, and behavioral data. Staff have authored numerous reports on educational measurement, including the BILOG-MG program, a leading item-response software package that features multiple-group as well as conventional IRT models for the analysis of dichotomously scored items. NORC staff worked on a series of methodological studies evaluating the feasibility of two-stage testing in large-scale educational assessments, and developed an innovative automated system for generating second-stage paper instruments, in which each sample member received a personalized booklet of items adapted to their ability in four areas of science.
Several recent NORC studies have included assessment components, including the National Longitudinal Surveys of Youth (NLSY79). The NLSY79 administers the PPVT and PIAT assessments to children aged 4 through 14. Currently, NORC is responsible for evaluating the properties of scales developed as part of the Getting on Track Early for School Success study sponsored by the Foundation for Child Development.