Low vs. High Fidelity Prototyping Debate
Low vs. High Fidelity Prototyping Debate 
The authors discuss the importance of low and high fidelity prototypes. The "fidelity" refers to the appearance, not the business logic. It seems that low fidelity prototypes are good enough for 80% of the user interfaces. Tips for the correct choice of protoype are provided at the end.
Low fidelity prototypes are inexpensive and can be build fast, but they fail to show navigation and flow, overlook design problems and leave low level design decisions to programmers. But high fidelity prototypes are expensive and consume lots of resources.
Table to summarize advantages and disadvantages. Tips for choosing the right prototype fidelity.
What percentage of the project resources should be reserved for prototyping to be most efficient?
Is it always best to create a high fidelity prototype? If not always, when is it?
What is the main disadvantage of a high fidelity prototype?