Hello everyone! My question is about regression models:

I have an experiment where men and women have to make indivdual decisions (they do it (=1) or they dont do it (=0); = Comp_i). Men (= 0) and women (= 1) are split equally into 3 different treatments (0 (=controlgroup), 1 and 2). I want to see if the decisions that the men and women have to make is influenced by the treatment.

Comp_i= ₀+₁female+₂treatment+₃feamle*treatment

Where: female = 0,1; treatment = 0,1,2; Comp_i= 0,1

How would it look like when I would like to add new variables, but they take value 1 to 4, for example? Do I just add them?

>>> For example: Comp_i= ₀+₁female+₂treatment+₃feamle*treatment+₄performance

Where: Comp_i= 0,1; female = 0,1; treatment = 0,1,2; performance = 1,2,3,4 (= as in 1^st, 2^nd, 3^rd or 4^th place in a group of 4) <<<

Or does more change? and when yes how?

Thanks in advance for any help!!! Really appriciate it!