" 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. Chicago Model Railroad 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. "

" Summary Chomsky and Herman summarize their theory thus: "A propaganda model has a certain initial plausibility on guided free-market assumptions that are not particularly controversial. In essence, the private media are major corporations selling a product (readers and audiences) to other businesses (advertisers). The national media typically target and serve elite opinion, groups that, on the one hand provide an optimal "profile" for advertising purposes, and, on the other, play a role in decision-making in the private and public spheres. The national media would be failing to meet their elite audience's needs if they did not present a tolerably realistic portrayal of the world. But their "societal purpose" also requires that the media's interpretation of the world reflect the interests and concerns of the sellers, the buyers, and the governmental and private institutions dominated by these groups (p. 303). " Empirical support Following the theoretical exposition of the propaganda model, Manufacturing Consent contains a large section where the authors seek to test their hypotheses. Layout Model Photo Railroad If the propaganda model is right and the filters do influence media content, a particular form of bias would be expected — one that systematically favors corporate interests. Noam Chomsky said, "the first way we tested the model in Manufacturing Consent was to submit it to what is really its harshest possible test: we let the opponents select their own ground. "