Prioritized Default Logic with Trust Values

A drawback of traditional default logic is that there is no general mechanism for preferring one default rule over another. To remedy this problem, numerous default logics augmented with priority relations have been introduced. In this paper, we show how trust values, derived from web-based social networks, can be used to prioritize defaults. We provide a coupling between the method for computing trust values in social networks given in (Golbeck 2005) and the prioritized Reiter defaults of (Baader & Hollunder 1995), where specificity of terminological concepts is used to prioritize defaults. We compare our approach with specificity-based prioritization, and discuss how the two can be combined. Finally, we show how our approach can be applied to other variants of prioritized default logic.