parameter interactions

hcarr01

 

Bonjour à tous,

 

Je me pose quelques questions par rapport aux interactions dans JMP.

J’essaye d’analyser l’impact de différents paramètres sur une variable Y.

 

A partir du modèle linéaire et de la régression des moindres carrés je crée des interactions entre les paramètres.

Par exemple JMP crée des interactions telles que : A*B, A*C...

 

Première question : Existe-t-il d’autres outils pour calculer les interactions entre les paramètres ?

Deuxième question : Lorsque JMP indique l’interaction A*B, comment il caractérise concrètement cette interaction ? Cela ne correspond pas à A multiplié par B.

 

Merci pour vos réponses.

Cordialement

statman

Here are my thoughts:

1. I'm not sure what you mean by other tools?  There are a number of methods to build/analyze models.  Typically models are analyzed using the fit model platform:

https://www.jmp.com/support/help/en/17.1/?os=mac&source=application#page/jmp/model-specification.shtml#ww431146

I personally like to visualize interactions, so interaction plots are quite useful.

2.  How JMP handles the estimation of interaction effects is dependent on the type of data (e.g., nominal, ordinal, continuous) and how the data was acquired. Interactions between variables are commonly coded as the product of two independent variables in statistical analysis. This practice is based on the concept of interaction effects, which refers to the combined effect of two or more variables on an outcome.  When the effect of a factor depends on another factor, this is an interaction. For continuous variables in an experiment, the levels are coded equidistant centered on zero (e.g., -1, 1 for 2-level factors).  The coding "normalizes" the coefficients to make analysis easier.  If you code your variables, then, indeed the interaction of A*B is the product of the main effects A and B:

A  B  A*B

-1 -1   1

1  -1  -1

-1  1  -1

1   1   1