Richard F. Potthoff

On the Johnson-Neyman technique and some extensions thereof

The Johnson-Neyman technique is a statistical tool used most frequently in educational and psychological applications. This paper starts by briefly reviewing the Johnson-Neyman technique and suggesting when it should and should not be used; then several different modifications and extensions of the Johnson-Neyman technique, all of them conceptually simple, are proposed. The close relation between confidence intervals and regions of significance of the Johnson-Neyman type is pointed out. The problem of what. to do when more than two groups are being compared is considered. The situation of more than one criterion variable is also considered.

Three-Factor Additive Designs More General Than the Latin Square

A class of designs are described for the case of three factors at levels m, n and p respectively for which the total number of experiments required is a fraction of mnp.

Four-Factor Additive Designs More General Than the Greco-Latin Square

This paper discusses a class of four factor designs in which the four factors are at m, n, p and q levels respectively, and in which the total number of runs is less than N = mnpq. All interactions are assumed nil.