FAQ/df - CBU statistics Wiki

Upload page content

You can upload content for the page named below. If you change the page name, you can also upload content for another page. If the page name is empty, we derive the page name from the file name.

File to load page content from
Page name
Type the odd characters out in each group: abz2a 125t7 HhHaHh year.s 5433r21 worl3d

location: FAQ / df

How do I work out degrees of freedom for terms in an ANOVA?

For N subjects and g group variables (factors) with respective levels L1, L2, ... , Lg and a within subjects factors, W, the table below gives the degrees of freedom for various types of sources variation in an analysis of variance.

Source of variation




2-way interaction


K-way interaction of factors

$$\prod_text{k} (L_text{k}-1)$$

Between subjects error terms

Error (one-way anova between subjects)

N - L1

Error (between subjects)

N - df of terms involving between subjects factors - 1

Within subjects error terms

Error (subjects x W1), no between subjects factor


Error (subjects x W1 x W2, no between subjects factor )


Error (subjects x W1 x W2, 1 between subjects factor)


Error (subjects x Within subjects interaction)

df of Error (between subjects) x df(Within subjects interaction term)


Boniface DR (1995) Experiment design and statistical methods for behavioural and social research. Chapman and Hall:London. (This book contains further details about computing degrees of freedom and also SS in balanced designs for terms in an ANOVA).