General Problem with Prototype Evaluation

The prototype may not be used in the same way as the final system — the tester may not be typical, training time may be insufficient, and slow response may cause evaluators to adjust their working style

Explanation

A general problem with prototyping is that the prototype may not necessarily be used in the same way as the final system. The tester may not be typical of system users, training time may be insufficient, and if the prototype is slow, evaluators may avoid features with slow response times — using the system differently from how they would use the final version.