The role of a cohort in the design and evaluation of pervasive systems

In this paper, we describe a new methodology for the design and evaluation of pervasive systems. We have recruited a cohort of 30 participants who are engaging with an interdisciplinary pervasive computing project Cityware over 3 years. The cohort has been selected in order to represent a broad mix of ages and technological abilities so as to increase the ecological validity of evaluation of systems and applications developed in Cityware. We discuss some of the techniques and methods that we have been able to employ as a result of maintaining this group of participants and illustrate how their data feeds into Cityware studies and applications. While the costs of recruiting and maintaining a cohort such as this are relatively high, the benefits in terms of the depth, richness and validity of results produced in this way are considered to be significant. We discuss this in terms of the potential for new designs, the type of data one can collect and engagement within the city.