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)

A proposed solution for the age x cohort x period issue in lifespan research uses all data, even with missing cells; can be used for repeated measures designs or designs in which new subjects are measured at each period; and allows assessment of each main effect and two-way interaction. (SLD)