9412265 Thompson Drs. Ian Thompson and Steven Majewski, at the Carnegie Institution, will participate on a collaborative project with Dr. Iain Reid, at Cal Tech, which involves the first systematic study of a classical starcount problem using modern detectors. Starcounts -- the stellar magnitude distribution as a function of Galactic latitude and longitude -- have served as an effective probe of the overall structure of our Galaxy for many years. Despite considerable interest in Galactic structure, little new starcount data have been published in the past decade. The aim of this project is to obtain deep, accurate observations with state-of-the-art detectors to test and improve on an interim Galactic model prepared by these researchers. With a profusion of parameters that define a starcount model (including the density laws, luminosity functions, and three-dimensional form of each population and sub-population) further observations are essential to test how well the interim model matches the Galactic structure. These researchers aim to produce a model of the Galaxy which is globally self-consistent and physically interpretable.