Probabilistic Semantics for Qualitative Influences

Book One

Volume

Proceedings of the AAAI Conference on Artificial Intelligence, 6

Engineering Problem Solving

What’s in an infiuence link? To answer this foundational question, I propose a semantics for qualitative influences: a positively influences b if and only if the posterior distribution for b given o increases with o in the sense of first-order stochastic dominance. By requiring that this condition hold in all contexts, we gain the ability to perform inference across chains of qualitative influences. Under sets of basic desiderata, the proposed definition is necessary as well as sufficient for this desirable computational property.