What does the F ratio mean in the ANOVA explanation?

Conditions

• There are multiple groups to compare.
• The comparison is framed in terms of variance components.

Reasoning, step by step

1. Identify the between-groups variance.
2. Identify the within-groups variance.
3. Calculate the ratio F = between groups / within groups.
4. Use this ratio to judge whether the group means differ enough to reject the null hypothesis.

Example

Slide shows the ratio written as F = between groups / within groups.

Common misconceptions

• Assuming the F ratio is a probability value rather than a variance ratio.

Watch the explanation

Explore next

• Why does a larger between-groups to within-groups ratio support rejecting the null hypothesis?
• What do the numbers 2 and 12 in $F(2, 12)$ represent?