Although Camp's tetrachoric correlation approximation has been shown to yield excellent results over a fairly wide range, its derivation remains something of a mystery. The present article shows how Camp might have arrived at his formula using a theoretical, rather than an empirical, approach.
Get full access to this article
View all access options for this article.
References
1.
Camp, B. H. (1934). The mathematical part of elementary statistics. Lexington, MA: D. C. Heath.
2.
Castellan, N. J. (1966). On the estimation of the tetrachoric correlation coefficient. Psychometrika, 31, 67-73.
3.
Cureton, E. E. (1968). Tetrachoric correlation by the Camp approximation. Educational and Psychological Measurement, 28, 239-244.
4.
Guilford, J. P. (1954). Psychometric methods (2nd ed.). New York: McGraw-Hill.
5.
Odeh, R. E. , & Evans, J. O. (1974). Algorithm AS 70: The percentage points of the normal distribution. Applied Statistics, 23, 96-97.
6.
Pearson, K. I. (1901). Mathematical contribution to the theory of evolution: VII. On the correlation of characters not quantitatively measurable. Philosophical Transactions of the Royal Society of London, 195A, 1-47.
