An interactive assessment system which was built around an existing computer controlled testing facility in the Department of Psychology at the University of Washington is described. The Extensible Multiprograming System for experimental psychology (EMPP) is problem oriented software developed to simplify the programing of psychological experiments. The system is capable of controlling several experimental stations where the same experiment can be performed synchronously or asynchronously at each of the stations, or where stations may be totally independent. This document also includes progress reports on the development and operation of the system, conference papers outlining the system and its language (PL/E), a discussion of the problems involved in designing an on line speech input terminal for the system, and a technical report on the study of individual differences in cognition. In addition, there are reports on choice reaction time and its role in ability measurement and on the information processing correlates of the Raven Progressive Matrices Test. (Author/MV)