I am working on a project that involves predicting the spread of aquatic macrophytes throughout the state of Illinois. I am using two conditions to predict. Acreage of lakes and secchi depth. (refelction of turbity) I have been using areal interpolation to execute the prediction and I am very close at finishing the project, however this is the first time I am using areal interpolation and I am unsure if my data is being referenced correctly. I have already incorporated the occured events and an areal interpolation has been generated. But I need that interpolation to have a reference to the lakes that events have not yet occured, or not yet been sampled. So my question is: When you are predicting to polygons after you have done an areal interpolation, there is an option to select append all fields from input features. When I use this option, is it referencing both the secchi and acres from this dataset to predict to polygons? Or do I need to find a way to incorporate the two datasets in the original areal interpolation when it asks for a population field under the rate (binomial) type.