I publish and talk on (Financial) Risk Model Validation. Two points:
- There's no point, indeed, in trying to falsify models, but they can be invalidated (for all kinds of reasons, and that might be temporary).
- Classical thinking about model validation (I usually show a diagram from a Schlesinger (1979) paper) starts with the modelling cycle:
Reality -> design -> conceptual model
Conceptual model -> implementation -> computerized model
Computerized model -> application -> reality
And it then accompanies the three steps with steps in the validation cycle:
Design <-> confirmation
Implementation <-> verification
Application <-> validation
So, validation in the narrow sense is dealing with actual use of an actual model implementation, which may be very different from intended use of a conceptual model (that would be dealt with in the confirmation step).
I publish and talk on (Financial) Risk Model Validation. Two points:
- There's no point, indeed, in trying to falsify models, but they can be invalidated (for all kinds of reasons, and that might be temporary).
- Classical thinking about model validation (I usually show a diagram from a Schlesinger (1979) paper) starts with the modelling cycle:
Reality -> design -> conceptual model
Conceptual model -> implementation -> computerized model
Computerized model -> application -> reality
And it then accompanies the three steps with steps in the validation cycle:
Design <-> confirmation
Implementation <-> verification
Application <-> validation
So, validation in the narrow sense is dealing with actual use of an actual model implementation, which may be very different from intended use of a conceptual model (that would be dealt with in the confirmation step).