" The term model is used in many communities with quite different traditions, commonly perceived problems, and purposes. To use the term properly therefore requires it being put into the right context . While this entry attempts to provide a general framework for talking about models it is not very likely that all communities would accept and use that framework. V. References [1] Stachowiak, H. ; "Modell" (In German); In: Seiffert, H. Handlexikon zur Wissenschaftstheorie; Deutscher Taschenbuch Verlag; 1989; pp. Balsa Airplane Model Kit 219 - 222. [2] Wieringa, R. "

" S. F. Novaes, Standard Model: An Introduction, hep-ph:0001283 I. Models are usually man-constituted. 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. Airplane Control Model Plan U 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. "