Addendum to SigDial 2013 Long Paper

In our 2013 SigDial paper, Interpreting Situated Dialogue Utterances: an Update Model that Uses Speech, Gaze, and Gesture Information, we noticed a mistake in the final derivation of our model. In the paper, equation 2 stands as:

old_model

However, P(U|R) can be rewritten as P(U,R) / P(R), which would result in cancelling out P(U|R) entirely, resulting in no mention of U in the model, which was certainly not our intention, nor was it how our model actually works.

Instead, R should have been kept on the left-hand side and then marginalized, resulting in an accurate depiction of our model:

fixed_model

This doesn’t change the arguments made in the paper and the results. We apologize if this has caused any confusion.