Systems of a rather different sort, aimed at clinically well-founded health counseling, have been under development as well. For example, the systems described in (Bickmore et al. 2011) rely on an extensive, carefully engineered formalization of clinically proven counseling strategies and knowledge, expressed within a description logic (OWL) and a goal-directed task description language. Such systems have proved to perform in a way comparable to human counselors. However, though dialogues are plan-driven, they ultimately consist of scripted system utterances paired with multiple-choice lists of responses offered to the client.