218 SmART ThIngS: UbIqUIToUS CompUTIng USeR expeRIenCe DeSIgn This combination of attitudes leads to a pathological situation where com- panies ship products that are simultaneously both conservative and half-baked, virtually guaranteeing either failure or unrepeatable success. When they fail, the company may not understand whether the technology was wrong, badly implemented, or that it did not go far enough. When these products succeed, the company may not know why either, because the functionality was not rig- orously defined. As buxton (2007) said, it is not just a question of getting the design right (developing/designing/engineering well), but getting the right design (developing the right thing). The way out of this dilemma -- of overly effortful prototypes that actually exclude exciting ideas from implementation -- is to aim for "just enough" prototyping. by simulating functionality wisely rather than exactly, the design team can explore key ideas and get a rich understanding of what is being done, and just as important, why, without having to spend energy and money making working devices. Chapter 14 described how to use observation and ideation to shape a design space around people's behavior and explore potential solutions within it. This chapter focuses on methods for further mapping the defined design space. Simulation uses ideas from theater and film to focus on the effect a technology induces in its audiences, whereas