References
- Evaluation Criteria, Educational Needs of Youth, (Washington, D. D.: The Cooperative Study of Secondary School Standards, 1950).
- Gage, N. L. (Ed.), Handbook of Research on Teaching (Chicago: Rand McNally and Company, 1963).
- Guilford, J. P., Psychometric Methods (New York: McGraw Hill Book Company, 1954).
- Hagan, E. and Thorndike, R. L., Encyclopedia of Educational Research, edited by Harris C. w. (New York: McMillan Company, 1960), pp. 482-485.