Evaluating early prototypes in context: trade-offs, challenges, and successes

We would like to say that experience prototyping and Wizard of Oz prototyping, taken together, constitute a suitable alternative to true contextual evaluation for early prototypes, one gaining realism at the expense of impartiality, the other impartiality at the expense of realism. As our experiences show, however, each pervasive application design poses unique challenges that you must consider when applying these approaches. Regardless, it's often a good trade-off to sacrifice some measure of realism to evaluate early prototypes. Evaluation of early pervasive computing prototypes in context is a pragmatic exercise, but one that is nonetheless informed by general approaches that reflect and adapt to the challenges of pervasive application development.