Dudley J. Cowden

An Application of Sequential Sampling to Testing Students

Abstract This paper provides an illustration of an application to the field of education of a technique hitherto used mainly in industry. The effect of systematic stratified sampling is briefly discussed.

The Multiple-Partial Correlation Coefficient

Abstract A partial correlation coefficient which is also a multiple correlation coefficient is discussed. Its relationship with other well-known coefficients is explained. Computational methods for computing the estimating equation and the correlation coefficient are suggested. * The writer wishes to thank Professors Harold Hotelling, George E. Nicholson, and John H. Smith for critically reading the manuscript and offering valuable comments. Professor Hotelling indicated the method of computation which he had suggested in an unpublished paper (see note 5). Professor Smith called the writers attention to some of the earlier references to the subject in the literature. Since the first draft of this paper was written (June, 1951), it has been learned that Professor C. Horace Hamilton, of the North Carolina State College of Agriculture and Engineering, has written an article entitled “Population Pressure and Other Factors Affecting Net Rural-Urban Migration,” in which the coefficient of multiple-partial corr...

Simplified Methods of Fitting Certain Types of Growth Curves

Abstract A method of selected points and a graphic method is presented for fitting the modified exponential, the Gompertz, and the logistic. The procedure is illustrated for the logistic.

A Procedure for Computing Regression Coefficients

Abstract Most statisticians are familiar with the method whereby partial correlation coefficients are derived from coefficients of lower order. But analogous methods for regression coefficients are apparently not widely known, and seem not to be described in the text books. Such methods are discussed here.