The present project is concerned with (1) the further validation of the extensive test battery given in 1948, against second-year grades, and (2) the development of new and revised tests for the third experimental battery. Tests found most predictive of second-year grades at the School were those in mathematics, physics, engineering, and reading comprehension. Validities against the second-year criterion were consistently lower than those against that for the first year, due probably in large part to the decrease in grade variability, drop-out, and decrease in inter-term correlation which were found to have occurred from the first to second years.