I am trying to figure out how to properly perform a "posthoc" analysis of an experiment in which I exposed subjects to 2 different treatments (drug A and drug B). Treatment A had 2 levels: treatment or no treatment. Treatment B had 2 levels: treatment or no treatment. We hypothesized that A is a toxic agent, and would reduce cell number. We hypothesized that B is a helpful agent, and would prevent toxic effects by A. A univariate anova found a significant interaction A*B : p <0.00001. A and B were also highly signficant. In SPSS, I set up a four column ANOVA. Column 1: Treatment A [0, 1]; Column 2: Treatment B [0, 1]; Column 3: Cell Number [scale value]; Column 4: Treatment [no A-noB, A-noB, B-noA, AB] I ran a regular ANOVA using columns 1, 2, and 3. I performed a "post hoc" analysis using column 4 and column 3 with a Tukey's test. Is there another way?
