Page 9 in Lucinda Crile, Review of Extension Studies - January to June 1950, Extension Service Circular 470, U.S. Department of Agriculture, Washington, D.C. July 1950. Summary of findings from analytic studies of four phases of extension work in Colorado, Colorado Agriculture College Extension, Fort Collins. 1950. Pages 1-31., Includes analysis of changes in teaching methods and activities by home demonstration agents in Colorado during that period, including use of telephones, circulars, and mass media.