Two-Way ANOVA

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Tap a term to see what it means, or .

Calculate

Example: the yield of plots with two fertilizers (factor A) and three irrigation levels (factor B), three plots in each combination. Does the fertilizer matter? The irrigation? And does the effect of irrigation depend on the fertilizer? Change the values to work out your own case.

Cells (one per row) In the order A1B1, A1B2, …, A2B1, …; all with the same number of replicates. Levels of factor B

Step by step

What each term means

Total Variation (SS_T): The sum of squares of all values around the overall mean.
Effect of A (SS_A): How far the means of each level of A are from the overall mean.
Effect of B (SS_B): The same for the levels of B.
Interaction (SS_AB): What the cell means have beyond the sum of the two effects: the effect of B changing with the level of A. On the chart, it shows as non-parallel lines.
Error (SS_E): The variation between replicates of the same cell — the noise each effect is measured against, in the F.

When to use it, assumptions and alternatives: two-way ANOVA in the statistical tests catalog.