Such models present themselves only rarely in a writer's life, and he couldn't resist the challenge.

The two models presented below take different approaches.

Critics agree that Nolan's model presents several shortcomings and is slightly out of date.

The model of learned helplessness has many appealing aspects and presents clear avenues for research.

The models present a few different ideas and scenarios.

PowerBook G3 and prior models presented it right side up to the computer's owner when the lid was closed.

However, as was mentioned earlier in the chapter, the model of perfect competition does not present an accurate picture of reality.

The model they presented related traffic flow to concentration (now typically known as density).

At that stage the model presents a good "fit" to the problem and good solutions can emerge.

Both models contain the same information, but presented differently.