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ttnphns
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gung - Reinstate Monica
gung - Reinstate Monica
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Contrasts Dummy coding for contrasts: 0,1 vs. 1,-1

I'm seeking your help in understanding the difference between two different contrasts for dichotomous variables.

On this page: http://www.psychstat.missouristate.edu/multibook/mlt08.htm under "Dichotomous Predictor Variables", there are two ways to code dichotomous predictors: using the contrast 0,1 or the contrast 1,-1. I kindakind of understand the distinction here (0,1 is dummy coding and 1,-1 adds to one group and subtracts from the other) but don't understand which to use in my regression.

For example, if I have two dichotomous predictors, gender (m/f) and athlete (y/n), I could use contrasts 0,1 on both or 1,-1 on both. What would be the interpretation of a main effect or an interaction effect when using the two different contrasts? Does it depend on whether my cells are of different sizes?

Thanks!

Contrasts: 0,1 vs. 1,-1

I'm seeking your help in understanding the difference between two different contrasts for dichotomous variables.

On this page: http://www.psychstat.missouristate.edu/multibook/mlt08.htm under "Dichotomous Predictor Variables", there are two ways to code dichotomous predictors: using the contrast 0,1 or the contrast 1,-1. I kinda understand the distinction here (0,1 is dummy coding and 1,-1 adds to one group and subtracts from the other) but don't understand which to use in my regression.

For example, if I have two dichotomous predictors, gender (m/f) and athlete (y/n), I could use contrasts 0,1 on both or 1,-1 on both. What would be the interpretation of a main effect or an interaction effect when using the two different contrasts? Does it depend on whether my cells are of different sizes?

Thanks!

Dummy coding for contrasts: 0,1 vs. 1,-1

I'm seeking your help in understanding the difference between two different contrasts for dichotomous variables.

On this page: http://www.psychstat.missouristate.edu/multibook/mlt08.htm under "Dichotomous Predictor Variables", there are two ways to code dichotomous predictors: using the contrast 0,1 or the contrast 1,-1. I kind of understand the distinction here (0,1 is dummy coding and 1,-1 adds to one group and subtracts from the other) but don't understand which to use in my regression.

For example, if I have two dichotomous predictors, gender (m/f) and athlete (y/n), I could use contrasts 0,1 on both or 1,-1 on both. What would be the interpretation of a main effect or an interaction effect when using the two different contrasts? Does it depend on whether my cells are of different sizes?

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Dan
Dan
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Contrasts: 0,1 vs. 1,-1

I'm seeking your help in understanding the difference between two different contrasts for dichotomous variables.

On this page: http://www.psychstat.missouristate.edu/multibook/mlt08.htm under "Dichotomous Predictor Variables", there are two ways to code dichotomous predictors: using the contrast 0,1 or the contrast 1,-1. I kinda understand the distinction here (0,1 is dummy coding and 1,-1 adds to one group and subtracts from the other) but don't understand which to use in my regression.

For example, if I have two dichotomous predictors, gender (m/f) and athlete (y/n), I could use contrasts 0,1 on both or 1,-1 on both. What would be the interpretation of a main effect or an interaction effect when using the two different contrasts? Does it depend on whether my cells are of different sizes?

Thanks!