I have conducted a 2-way ANOVA and obtained a significant Main Effect in IV1 and IV2, but a non-significant interaction. Following that, I have analyzed IV1 using a test for Simple Effects and received a significant Simple effect at level 1 and a non-significant simple effect at level 2.
To speak in particularities of my experiment: I tested the main effect of sex (factor 1) and treatment (factor 2). The interaction between the main effects was non-significant (p = .279), but the main effects were both individually significant (sex, p = .008 and treatment, p = .022). I proceeded to run a simple effects test and identified significance in males (p = .016) and non-significance in females (p = .388). Without the simple effects test I wouldn't be able to distinguish the efficacy of drug treatment in males versus females. Surely the simple effects test was necessary to run in this case, contrary to the non-significant main interaction? Is there something I am missing that would counter my interpretation of the treatment being non-efficacious in females?
I am under the understanding that because of the non-significant interaction, completing a simple effect test was deemed "unnecessary". I don't understand why the simple effect test is only completed following the presence of a significant interaction of main effects. Can anybody explain how the Simple Effect test is influenced by the interaction, and how I would interpret my Simple Effect results accordingly?