Evaluating software for communities using social affordances

In this paper we discuss the problems faced when building software for communities. In particular, we introduce the formative evaluation method that emerged while developing two social network sites (SNSs). We acknowledge that the success of software for communities is due, in part, to the network effect, which is difficult to predict. We also acknowledge that traditional usability (e.g., individual user performance) is required, but not sufficient, for the success of a social network. We hypothesize that a missing piece of current evaluations are the social affordances provided by the system and how well they encourage users into social action. In this paper we present the rationale behind our evaluation, two examples of the evaluation, and discuss the evaluation's utility and future work.