When we compare our control with another group, the t-test could fit our goal very well. But when we need to compare it into more than 1 group, 3 groups for example, the t-test could only give the random false positive independently. That means three false positives in three comparisons. This would cause a problem. Because the false positive we need to consider now is at least one false positive in three comparisons. It means we need to adjust the p-value and apply a rigorous method to achieve a more reliable result. For doing that, ANOVA was introduced and applied.