glass was born in lincoln, nebraska and educated in the lincoln public school system, graduating from lincoln, northeast high school in 1958. he attended nebraska wesleyan university from 1958 to 1960 and the university of nebraska-lincoln from 1960 to january, 1962, earning a bachelor's degree with a joint major in mathematics and german. he worked as a research assistant for robert e. stake at unl from spring 1961 until graduation. at stake's suggestion, he chose to immediately enroll in graduate school. he entered the phd program in statistics, measurement and experimental design at the university of wisconsin, madison in february 1962. he graduated with a phd in educational psychology in may, 1965, having studied with julian c. stanley, chester w. harris, and henry f. kaiser. his doctoral dissertation, entitled alpha factor analysis of infallible variables, won the creative talent award in psychometrics given by the american institutes for research for 1966. in august 1965, he joined stake and other colleagues as an assistant professor in the center for instructional research and curriculum evaluation at the university of illinois at urbana–champaign, where he taught for two years before moving to the university of colorado boulder. he was promoted to professor at cu-boulder in 1970. in 1986, glass joined the faculty of the arizona state university in tempe, arizona, from which he retired in 2010. he holds the title of regents' professor emeritus from arizona state university. in 2011, he joined the faculty of the school of education at the university of colorado boulder as a research professor. he has served as a senior researcher in the national education policy center since 2010.