When to Use Paper - Paper Prototyping: The Fast and Easy Way to Define and Refine User Interfaces - page 239

Chapter 14: When to Use Paper
Chapter 12 looked at the kinds of questions that paper prototypes can (and can't) answer about your
interface. In this chapter we look at circumstances of your project that can nudge you toward or away
from using paper. In this chapter I assume that you've decided paper is a viable technique for what you
want to learn but you're still debating whether testing a paper prototype would make sense for your
project as opposed to testing some other version of your interface. If you've already made your decision
about using a paper prototype, you can skip this chapter.
War Stories
In 10 years of usability testing, I've collected a number of " war stories " of usability tests (and sometimes
whole usability studies) gone horribly awry, with consequences ranging from funny to frustrating. Here's
a sample that will give you a sense of what can happen. All of these stories are true, although details
have been omitted to protect the embarrassed.