## Visualizing a Continuous by Continuous Interaction in Linear Regression

View high res version here. “Did you see if there was a difference by [insert the person’s favorite population or topic of interest].” With a resigned response I reply “No I haven’t, but that is a good idea.” I’ve had this exchange in every research talk I’ve given. Often times we are interested in understanding how one group varies by another when predicting an outcome. This can be examined via an interaction term in a regression model. An interaction term…