Unbalanced 2 x 2 Factorial Designs and the Interaction Effect: A Troublesome Combination

Unbalanced 2 x 2 Factorial Designs and the Interaction Effect: A Troublesome Combination

In this power study, ANOVAs of unbalanced and balanced 2 x 2 datasets are compared (N = 120). Datasets are created under the assumption that H1 of the effects is true. The effects are constructed in two ways, assuming: 1. contributions to the effects solely in the treatment groups; 2. contrasting contributions in treatment and control groups. The main question is whether the two ANOVA correctio...

Optimal Designs for 2 Factorial Experiments with Binary Response

We consider the problem of obtaining D-optimal designs for factorial experiments with a binary response and k qualitative factors each at two levels. We obtain a characterization of locally D-optimal designs. We then develop efficient numerical techniques to search for locally D-optimal designs. Using prior distributions on the parameters, we investigate EW D-optimal designs that maximize the d...

2-level Fractional Factorial Designs Which Are the Union of Non Trivial Regular Designs

Every fraction is a union of points, which are trivial regular fractions. To characterize non trivial decomposition, we derive a condition for the inclusion of a regular fraction as follows. Let F =

A 2 X – WEB PAGES on LATTICES and SPHERICAL DESIGNS

Tests for the homogeneity of two binomial proportions in extremely unbalanced 2 x 2 contingency tables.

Asymptotic tests such as the Pearson chi-square test are unreliable for testing the homogeneity of two binomial probabilities in extremely unbalanced cases. Two exact tests (conditional and unconditional) are available as alternatives and can be implemented easily in StatXact 6.0. In equal sample cases it is well known that the unconditional exact test is more powerful than the conditional exac...