analysis

How to visualize interaction effects

I recently gave a workshop on data visualization. One of the topics was visualizing interaction effects (or “moderation” analyses). I think it is a great topic because it exemplifies quite well that there is not one solution to all problems. In general, I would argue that trying to visualize interaction effects is great idea. Due to the conditional nature of the effects obtained from standard regression analyses that include an interaction term, it is often… Read More »How to visualize interaction effects

How to center in multilevel models

Ever thought about centering your variables before running an regression based analysis? From my personal experiences with students, chances are high that you haven’t. Although a useful data transformation procedure for many different types of statistical analyses, centering is seldom taught in fundamental statistic courses. Although the mathematical principles behind it may seem arbitrary, its effects on results are oftentimes quite strong. Centering is useful in standard statistical modeling (e.g., OLS regression), but its usefulness… Read More »How to center in multilevel models