In this module, we will discuss how one can assess the quality of different models, and what aspects of model quality one needs to consider.
If we fit any kind of statistical model to data, we need to determine the quality of a fit somehow. How do we know one model is better than another? How do we know any given model is good? These questions, i.e., what model is better among a group of models, and if a model is good (even the best among a group of awful models can be a bad model!) have multiple parts to them, only some of which can be answered by statistics. Others are judgment calls.
There is no single way to define quality. Instead, multiple factors should be considered. Here are some important aspects to think about:
We will discuss these different ways one can assess model quality in this module.