Offline model testing encompasses all the model-evaluation processes that are performed before the model is deployed. Before discussing online testing in detail, we must first define model errors and ways to calculate them.
Offline model testing
Understanding model errors
Every model can make mistakes because collected data, and the model itself, introduces implications about the nature of your problem. The best example of a good working model is inside your brain. You use modeling in real time—the brain renders everything you see by interpreting electromagnetic impulses recorded by your eyes. While this picture of the world is imperfect, it is useful as we receive over 90% of information through the visual channel...
