" The distinction between descriptive and prescriptive reference mode goes at least back to Wieringa, [2]. More detail and references regarding models and modeling can be found, e . g. , in [3]. II. The consistency of models may be conceptual or physical. In many areas of research conceptual models have become the dominating species, as conceptual models, more easily than physical ones, can be investigated by means of computing. High Model Powered Rocket For conceptual models to be the shared property of a research community the concepts they involve must be capable of being shared. That is the case when a consensual understanding of these concepts has been achieved or can be achieved by means of definition, examples, etc. "

" 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. 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. Code Model Rocket Safety Also other properties of O may not be properties of M. In that sense a model is more abstract than its original. "