A system may actually exist as a natural aggregation of component parts found in Nature, or it may be a man-contrived aggregation – a way of looking … - C. West Churchman

Knowledge is a potential for a certain type of action, by which we mean that the action would occur if certain tests were run. For example, a library plus its user has knowledge if a certain type of response will be evoked under a given set of stipulations.

If the chance of error alone were the sole basis for evaluating methods of inference, we would never reach a decision, but would merely keep increasing the sample size indefinitely.

In general, we can say that the larger the system becomes, the more the parts interact, the more difficult it is to understand environmental constraints, the more obscure becomes the problem of what resources should be made available, and deepest of all, the more difficult becomes the problem of the legitimate values of the system.