" That implies firstly that M does not have the properties of O that prevent I from investigating O. Also other properties of O may not be properties of M . In that sense a model is more abstract than its original. Secondly, a model M will in general have properties that O does not have and that actually aid I in investigating M. What the investigator I does in modeling is formulating a problem P in terms of the original O, translate that problem into a problem P' in terms of M, obtain a solution S' of P' and translate S' into a solution candidate S of P in terms of O. If S is actually a solution of P then the modeling process was successful and can be terminated. If, however, that is not the case then the investigator I can start over with a different problem, model, means of investigation, or relation between model and original. Antique Model Car It is worth noting that the concept of solution to a problem depends on the investigator, its purpose, intended means of investigation, time-horizon of that investigation and so forth. What has been presented here so far essentially is due to Stachowiak, [1]. "

" Model-View-Controller (MVC) is a software architecture that separates an application's data model, user interface, and control logic into three distinct components so that modifications to one component can be made with minimal impact to the others. MVC is often thought of as a software design pattern. However, MVC encompasses more of the architecture of an application than is typical for a design pattern. Hence the term architectural pattern may be useful (Buschmann, et al 1996), or perhaps an aggregate design pattern. Operation In broad terms, constructing an application using an MVC architecture involves defining three classes of modules. Model: This is the domain-specific representation of the information on which the application operates. The model is another name for the domain layer. Porsche Model Car Domain logic adds meaning to raw data e. g. "