Is there any statistical test or work-around to test whether the effect of variable a on c increases if b is high? All variables were asked for on a 7-point likert scale.
I thought about performing a regression with only the cases where b is above 4 and then comparing the regression with another one where b is below 4, but I dont know if this would be a good way to do it? And if so, which measures do I have to compare except for the regression coefficient? R-squared or which others?
Any thoughts on this?