Question

What is the advantage of using ANOVA to test for differences among treatment means rather than testing all possible pairs of treatment means?

Answer 1

The fact that the ANOVA can test more than one treatment is a major advantage over the t - test. It opens up many testing capabilities.

The issue in testing all possible pairs of treatment means is the question of the probability of Type I errors. Most differences among alternative techniques result from different approaches to the question of how to control these errors.

In testing all possible pairs of treatment means the more hypothesis tests we use, the more we risk making a Type I Error and the less power a test has. This is the advantage of using ANOVA to test for differences among treatment means rather than testing all possible pairs of treatment means.