Trust and the Semantic Web

Trust has long been foreseen as challenge for the Semantic Web research community, appearing in the upper echelons of the Semantic Web Layer Cake technology stack, however Semantic Web research around the topic of trust does not seem to have a clear idea of what exactly this challenge is. Jen Golbeck's prominent work with Semantic Web technologies has harnessed trust within social networks, putting it to tasks such as Email filtering and film recommendation, unfortunately this does not really shed any light on the role trust might play in the Semantic Web technology stack. If we unpack our expectations of a Semantic Web trust layer, taking the time to consider what we expect it to achieve,  by what questions we wish to be able to ask of it, we generally arrive at two questions:
  1. Can I rely on this piece of information?
  2. Can I trust this service provider?
These two questions are fundamentally different; the first pertains to the truth of a piece of information, whereas the second concerns the probable behaviour of another agent. However both are similar in that they require a judgement to be made based on information such as provenance and reputation. To construct a trust layer we require both the capacity to make such judgements and the information on which to ground such decisions, both of which represent sizable research challenges. The Semantic Web trust layer will not be a single technology, rather a collection of interacting techniques and standards whose emergent macro phenomena we must engineer to be trust.