Two pioneering public radio stations--WOSU-AM, licensed to the Ohio State University in Columbus, and WHA-AM, licensed to the University of Wisconsin in Madison--conducted audience research as early as the 1920s. The challenge for early education broadcasters became to adapt the existing audience research paradigm to their purposes, or to develop a new, more appropriate model. The earliest attempts (in 1923) at audience research by these stations was to determine whether communication by radio had indeed taken place. Both stations also analyzed mail received from listeners to gauge reaction to programming decisions. Research during the 1930s was promoted by the close relationship between WOSU and Ohio State's Bureau of Educational Research. The Institute for Educational Radio, an annual conference held at Ohio State between 1930 and 1953, created a forum for educators and broadcasters to discuss issues of educational broadcasting. Audience studies declined during the years of World War II. In 1946, Harrison B. Summers brought an interest in commercial broadcasting and audience research methods to Ohio State. He conducted numerous research studies during his 18 years on the Ohio State faculty, providing WOSU with a wealth of audience data. By the 1950s, interest in audience research was slowly spreading throughout educational broadcasting. Using research to justify institutional support remained important after passage of the Public Broadcasting Act of 1967. Issues raised by audience research reflect the still unresolved mission-versus-market debate in public broadcasting. (Eighty-two notes are included.) (RS)