Hi In the GLM chapter on page 41, the notes ask a question - "what is the difference between correlations and interactions?" The answer given is "Correlations occur when there is a relationship between the distribution of exposure between levels of two or more factors. GLMs automatically take account of correlations (unlike one-way tables). Interactions relate to the effect that factors have upon the risk. To define the risk accurately, an interaction would be necessary where the effect of two (or more) factors depend on each other." Can anyone give an example of a correlation vs an interaction to help illustrate this please? Thanks
