Since its founding in 1947, ETS has conducted a significant and wide-ranging research program that has focused on, among other things, psychometric and statistical methodology; educational evaluation; performance assessment and scoring; large-scale assessment and evaluation; cognitive, developmental, personality, and social psychology; and education policy. This broad-based research program has helped build the science and practice of educational measurement, as well as inform policy debates. In 2010, we began to synthesize these scientific and policy contributions, with the intention to release a series of reports sequentially over the course of 2011 and 2012. This paper, written by Samuel Ball, was originally published in 1979. It is the only reissue in the series but is a fitting inaugural: The report documents the vigorous program of evaluation research conducted at ETS in the 1960s and 1970s, which helped lay the foundation for this fledgling field.