Differences between 3 or more unrelated samples

Question 1

What are the parametric and non-parametric tests used to find the difference between 3 or more unrelated samples?

Answer 1

Parametric - One-way ANOVA

Non-Parametric - Kruskal-Wallis

Question 2

What extra stage is there with the One-way ANOVA which you cannot find with any other test?

Answer 2

Post hoc Multiple Comparison test.

- test used if the one-way anova is significant

Question 3

Why is the post hoc test used?

Answer 3

1. A significant result from an ANOVA test only tells you that at least 2 of your samples differ by more than chance alone.
2. Post hoc tell us which samples differ significantly from which other sample(s)

Question 4

What results do you get from an ANOVA test?

Answer 4

It generates a test statistic called F and a P -value.

Question 5

Important points for Kruskal-Wallis test

Answer 5

1. It is the Non-parametric sibling
2. Does not come with a post hoc test
3. the test statistic is Chi squared (X2) (along with df and p-value)