1. Studies of the conditioning of verbal behavior.
2. Miller, Gerald R. 1961. “The Effect of Varied Incentive Conditions on the Oral Presentation of a Second Speaker,”. Iowa unpubl. diss.
3. Estimation of the reliability of ratings
4. Guilford, J. P. 1954.Psychometric Methods, 395–397. New York: McGraw‐Hill Book Company, Inc.
5. Lindquist, E. F. 1956.Design and Analysis of Experiments in Psychology and Education, 267–273. Boston: Houghton Mifflin Co.