Dropping the interaction term when the interaction effect is not significant?

Question

Can I drop the interaction term from the model if the interaction term is insignificant?

score 1 · Accepted Answer · answered Nov 25 '14 at 09:03

1

If the purpose of your analysis is to say something about the interaction term, then it is more convincing to keep the interaction in and show that it is not significant.

answered Nov 25 '14 at 09:03

Maarten Buis

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And by keeping it you will preserve type I error and unbiasedness of the estimate of residual variance. – Frank Harrell Nov 25 '14 at 13:09

Dropping the interaction term when the interaction effect is not significant?

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