**Simple effects tests**are follow-up

**tests**when the interaction is significant. They explore the nature of the interaction by examining the difference between groups within one level of one of the independent variables.

Similarly one may ask, what is a main effect and interaction?

**Understanding Main Effects and Interactions**. A

**main effect**is the

**effect**of a single independent variable on a dependent variable – ignoring all other independent variables. For

**example**, imagine a study that investigated the effectiveness of dieting and exercise for weight loss.

What is a main effect?

In the design of experiments and analysis of variance, a

**main effect**is the**effect**of an independent variable on a dependent variable averaging across the levels of any other independent variables.What are the main effects in Anova?

In statistics, a

**main effect**is the**effect**of one of just one of the independent variables on the dependent variable. When there are two independent variables, you should use a two-way**ANOVA**to determine if the**main effects**or interaction**effect**are statistically significant.