James Paul Gee from Arizona State University put it best when he said:
We take it as completely natural that you would be in an Algebra class for 12 weeks, and then I would give you a test on Algebra …. to see if you learned any Algebra. Let’s say a kid plays Halo on Hard …. and finishes Halo. Would you be tempted to give him a Halo test? No. Not at all. You’d say the game already tested him. So let’s think - Why is it that we’re not tempted to give him a Halo test, but we are tempted to give that Algebra test and use that as a judgement? We’ll its because you actually trust the design and learning of Halo better than you trust the design and learning of that Algebra class.