Refined modeling of sensor reliability in the belief function framework using contextual discounting

In belief functions theory, the discounting operation allows to combine information provided by a source in the form of a belief function with meta-knowledge regarding the reliability of that source, resulting in a “weakened”, less informative belief function. In this article, an extension of the discounting operation is proposed, allowing to use more detailed information regarding the reliability of the source in different contexts, i.e., conditionally on different hypotheses regarding the variable on interest. This results in a contextual discounting operation parameterized with a discount rate vector. Some properties of this contextual discounting operation are studied, and its relationship with classical discounting is explained. A method for learning the discount rates is also presented.