In: Statistics and Probability
The assumptions of ANOVA are
In one-way anova the degrees of freedom(df) of treatment effects(between group) is k-1 and that of error(within group) is n-k. Hence the total df is n-1. Here there are n independent random sample observations classified into k classes.
The pro is
• More costly
The con is
It often leads to misleading results.
Post hoc tests are an integral part of ANOVA. When you use ANOVA to test the equality of at least three group means, statistically significant results indicate that not all of the group means are equal. However, ANOVA results do not identify which particular differences between pairs of means are significant. Use post hoc tests to explore differences between multiple group means while controlling the experiment-wise error rate.
Tukey's method is a post hoc test.