The testing of private capital on Beijing's subway line — bringing with it the MTR's punctilious management skills — is an unlikely but crucial experiment as the city struggles to catch up with ridership demand (the network's length, as this map illustrates, is set to double again by 2015). (treehugger.com)
Science also uses such models to generate insight, especially when direct empirical verification is impossible, although they may be indirectly verified in crucial experiments. (religion-online.org)
In discussing the billiard - ball model he writes: «Models of this sort are not normally shown to be true or false by crucial experiments; it is rather that they work well or badly for particular purposes, and when they work badly they gradually fall into disuse. (religion-online.org)