In The Treachery of images, a famous painting by René Magritte, the artist painted the tobacco pipe depicted in Figure 1, labeled it with the caption "Ceci n'est pas une pipe.", or "This is not a pipe". He later remarked:
The famous pipe. How people reproached me for it! And yet, could you stuff my pipe? No, it's just a representation, is it not? So if I had written on my picture 'This is a pipe', I'd have been lying!
Magritte's work highlights that even through a painting of a pipe may be used for many purposes, none include smoking tobacco. J. Rothenberg captures the essence of making such representations of reality in the Nature of Modeling:
Modeling, in the broadest sense, is the cost-effective use of something in place of something else for some cognitive purpose. It allows us to use something that is simpler, safer or cheaper than reality instead of reality for some purpose. A model represents reality for the given purpose; the model is an abstraction of reality in the sense that it cannot represent all aspects of reality. This allows us to deal with the world in a simplified manner, avoiding the complexity, danger, and irreversibility of reality.
Metamodeling, or more formally, metadata modeling involves the conceptual abstraction ('meta') of models themselves. This process of abstraction involves integrating theory, concepts, configurations, rules, and constraints. The results must be adequate for the analysis, construction, and development of models that conform to the metamodel they are subordinate to. As in Magritte's painting, there is a recursive nature to these representations, as they must apply to a variety of modeling environments, representing: