EVALUATION OF INPUT DATA
Two types of data in model development:
1) the design data or information used to construct the model
2) the input data of data used to stimulate the system
Data collection and verification may well be the most overlooked portion of model construction.
Textbooks contribute to the problem because the data is often presented directly.
The process of data collection often consumes the major amount of time and resources when dealing with actual problems.
Good practice: First decide on the basic form of the model, then identify its specific data needs.