Q. What is ANOVA and when is it used?
ANOVA stands for Analysis of Variance. A one-way ANOVA is used to analyze the effect of a factor variable with k levels on a numeric response. For example, if you were analyzing the blood pressure of study participants by gender, you would use a one-way ANOVA with two levels (male and female). The ANOVA will determine if there is a statistically significant difference between the mean blood pressure for male and female participants.
You can also perform a two-way ANOVA if you need to analyze the effect of two factor variables instead of just one. You would use a two-way ANOVA if you wanted to add whether or not the participant exercised prior to the blood pressure measurement as a factor in the analysis.