" That justifies talking about their purpose prior to talking about their consistency. Models are used as substitutes for originals because properties of the latter are of interest and the originals are not going to be investigated themselves . There may be a number of reasons for that such as taboos preventing from studying the original itself, or inability, the involved cost in terms of resources or moral damage being intolerable, or similar. For an investigator I it makes only sense to consider an entity M as a substitute of an entity O, if I can (1) establish an analogy, similarity, or similar relation between M and O that permits the substitution of O by M with respect to purpose and means, time-horizon etc. , and (2) I can actually investigate M in the required way. 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. Guy Hot Model 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. "

" For more information, see: Event-driven_programming Implementations The pattern was first described in 1979 by Trygve Reenskaug, then working on Smalltalk at Xerox research labs. This original implementation inspired many other GUI frameworks such as: The NeXTSTEP and OPENSTEP development environments encourage the use of MVC. Cocoa, based on these technologies, also uses MVC. Microsoft Foundation Classes (MFC). The Java Swing GUI library. More recently there have been attempts to apply MVC architectures for web-based interfaces. In the design of web applications, MVC is also known as a "Model 2" architecture in Sun parlance. Asian Hot Import Model Complex web applications continue to be more difficult to design than traditional applications, and MVC is being pushed as a potential solution to these difficulties. Beware: many applications which claim to comply with this much misunderstood pattern in fact do not achieve the required separation of model and view. "