Notes that presence of heterogeneous regression slopes in an analysis of covariance design is equivalent to presence of interaction in randomized-blocks design. Describes modification of the usual graphical representation of heterogeneous regressions that can aid in interpreting significant regions for regression surfaces. (NB)

Several general correlation patterns are shown which give exact F tests in an analysis of variance (ANOVA) procedure. They are the most general correlation patterns one can assume in a one-way and two-way layout and still have the F tests be valid. (Author/BW)

Using data from a sales campaign for the Arizona State lottery, a multiplist strategy of program evaluation is analyzed. Several complementary designs are used within the strategy to help remove threats to internal validity associated with the nonequivalent control group design. (SLD)

A study was conducted to determine the effect of graphic format--bar, line, table, and line-table graph--on the interpretation of numerical data by field dependent and field independent students. Ninety-six undergraduate students were given the Group Embedded Figures Test and randomly assigned to one of four treatments. During the testing phase,…

This study of the effects of computer-assisted instruction (CAI) on the academic achievement of educationally disadvantaged students in grades 2 through 8 in four urban schools tested three hypotheses: (1) supplementary CAI programs are significantly more effective than non-CAI supplementary instruction approaches for disadvantaged students; (2)…