Title: Modeling the Ellsberg Paradox by Argument Strength,
Abstract: We present a formal measure of argument strength, which combines the ideas
that conclusions of strong arguments are (i) highly probable and (ii) their
uncertainty is relatively precise. Likewise, arguments are weak when their
conclusion probability is low or when it is highly imprecise. We show how the
proposed measure provides a new model of the Ellsberg paradox. Moreover, we
further substantiate the psychological plausibility of our approach by an
experiment (N = 60). The data show that the proposed measure predicts human
inferences in the original Ellsberg task and in corresponding argument strength
tasks. Finally, we report qualitative data taken from structured interviews on
folk psychological conceptions on what argument strength means.