Evaluating competing agent strategies for a voice email agent

This paper reports experimental results comparing a mixed-initiative to a system-initiative dialogue strategy in the context of a personal voice email agent. To independently test the effects of dialogue strategy and user expertise, users interact with either the system-initiative or the mixed-initiative agent to perform three successive tasks which are identical for both agents. We report performance comparisons across agent strategies as well as over tasks. This evaluation utilizes and tests the PARADISE evaluation framework, and discusses the performance function derivable from the experimental data.