# Contrasts: Possible in Factorial Anovas or only On-way Anovas?

#### Jamie Farquhar

##### New Member
Contrasts: Possible in Factorial Anovas or only One-way Anovas?

I would like to set up some contrasts in my factorial anova so that I can look for possible interactions between factor A and the contrasts of factor B. From my reading, it doesn't seem to be possible. All of the guides seem to refer to one-way anovas exclusively (e.g., http://www.statisticshell.com/contrasts.pdf). Any ideas? Thank you!

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#### Dason

I don't what you mean by "interactions between factor A and the contrasts of factor B" but contrasts are definitely possible in a factorial setting.

#### Jamie Farquhar

##### New Member
I don't what you mean by "interactions between factor A and the contrasts of factor B" but contrasts are definitely possible in a factorial setting.

I hope this clarifies my question. Factor A has 3 levels, and Factor B has 2 levels. I would like to set up a contrast with Factor A (e.g., 0, -1, 1) and determine if this contrast interacts with Factor B (i.e., does the contrast look different at the two different levels of factor B).

How would I go about setting this up in a single factorial anova? Thanks!

#### Dason

So Let's let A1B1 refer to the cell mean corresponding to the first level of A and the first level of B. You're interested in whether (A3B1 - A2B1) - (A3B2 - A2B2) = 0

Yes this is very possible to do and depending on what software you use isn't hard to code up.

#### Jamie Farquhar

##### New Member
Dason, that is great news. I am using SPSS. Do you have any examples of the required syntax, or a reference to a guide or article that describes this process? Thank you!