As implied in the question, I have one bothersome variable called "merit value" which has different scales depending on which group the student was accepted from.
The groups are:
Grades - Scale: 10-22.5 SAT equivalent - Scale: 0-2 Community college - Scale: 1-4
So far I've been reluctant to use this as an independent variable in my regression analysis. Not just because of the different scales but because of their different interpretation. For instance, my material indicates that it's much more difficult for a student to achieve a high score on our SAT equivalent than it is to achieve a high grade.
My technical supervisor has suggested I use standardized beta coefficients in order to even out these differences and in order to convert the variable values to a common scale.
Is this the proper solution in this case or might there be some unforseen consequences?