Steps for the Application of the Johnson-Neyman Technique-A Sample Analysis

In a recent investigation by one of the above authors, an attempt was made to dis cover if certain underlying characteristics distinguish excellent achievers from poor achievers in two-figure division. A screening test in two-figure division was administered to 283 pupils in 6B classes in 9 elementary schools. After the 283 pupils were found to be homogeneous in division with respect to both variability and mean achievement, they were grouped as one distribution. The upper one-third, the 90 best achievers, were selected as excellent achievers, and the lower one third, the 90 poorest achievers, were selected as poor achievers. The two groups were then measured on a number of factors thought to be associated with ability in two-figure divi sion. The two groups were first compared on these factors by means of the t test for the significance of the difference between two means. This comparison showed that excel lent achievers were significantly superior to poor achievers on all factors.