What Paper is (and isn't) Good for

Paper prototyping is a useful technique, but it is not perfect. This chapter outlines the kinds of usability problems that paper prototyping is likely and unlikely to find in an interface. It also discusses the kinds of problems faced in paper prototyping and describes some issues for which usability testing in general (whether paper or computer) is not the best means of discovery. Paper prototyping is a good technique. There are different ways to look at prototypes, but the most useful consists of four dimensions: breadth, depth, look, and interaction. Breadth refers to the percentage of the product's functionality that is represented in the prototype; Depth is the level of detail that's implemented including robustness; the Look is determined by inspection and is gives rise to the original concept of prototype fidelity; and Interaction refers to the way the prototype handles the inputs and outputs with the user. Time is an integral part of interaction, so things such as response time, cursor changes, flashing lights, and animation must be considered.