A Generative Model for User Simulation in a Spatial Navigation Domain

We propose the use of a generative model to simulate user behaviour in a novel task-oriented dialog domain, where user goals are spatial routes across artificial landscapes. We show how to derive an efficient feature-based representation of spatial goals, admitting exact inference and generalising to new routes. The use of a generative model allows us to capture a range of plausible behaviour given the same underlying goal. We evaluate intrinsically using held-out probability and perplexity, and find a substantial reduction in uncertainty brought by our spatial representation. We evaluate extrinsically in a human judgement task and find that our model’s behaviour does not differ significantly from the behaviour of real users.