Summary
Compares means across three or more groups by partitioning variance.
In depth
One-way ANOVA tests whether means of three or more groups differ using the F ratio (between-group variance / within-group variance). Post-hoc tests (Tukey) identify which groups differ. Assumes normality and equal variance.
ANOVA tells whether any group differs, not which ones. Two-way ANOVA tests two factors and interaction. Repeated-measures versions handle paired data.
Example: testing three drug doses plus control.
Frequently asked questions
What is ANOVA?
Compares means across three or more groups by partitioning variance.
Which area of biology covers ANOVA, and how advanced is it?
ANOVA is one of the 51 topics in Lab Methods & Biostatistics. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include t-Test, Chi-Squared Test, P-Values and Multiple Testing.
Can you give an example of ANOVA?
Comparing growth on four fertiliser treatments.
What should I learn before ANOVA?
Work through the Beginner topics in Lab Methods & Biostatistics first, such as Scientific Method, Hypothesis, Variables, then return to ANOVA. Advanced topics assume the Intermediate vocabulary.
What topics are related to ANOVA?
The closest topics to ANOVA are t-Test, Chi-Squared Test, P-Values and Multiple Testing, Standard Deviation. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand ANOVA?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for ANOVA. To practise the whole of Lab Methods & Biostatistics, use the Lab Methods & Biostatistics quiz.
How is ANOVA different from t-Test?
ANOVA: Compares means across three or more groups by partitioning variance. t-Test: A test for significant differences between the means of two groups. Read both side by side and note what each one explains.
How should I study ANOVA step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with t-Test and explain the difference aloud. Finally, take the Lab Methods & Biostatistics quiz and come back to this page for any question you miss.