Tailoring coaching conversations with virtual health coaches

A healthy lifestyle is important for our well-being and can prevent illnesses, but changing our behaviour to follow a lifestyle can be difficult. Digital health (eHealth) applications can support people in this process. However, their use decreases rapidly when the novelty effect wears off. Two causes for this are the lack of human involvement and the lack of personalised content. Therefore, conversational agents are added to eHealth applications in the role of health coaches to provide a social incentive, and adjustment of their dialogue content to users is investigated to increase personal relevance (tailoring). Such tailoring has previously been found to be effective in eHealth applications but has not extensively been investigated for interactive two-way communication over a longer period of time, such as in coaching conversations. The objective of this thesis research was therefore to address the following question: “How can we tailor users’ coaching conversations with conversational agents to improve engagement?”

To that end, this thesis describes the development of dialogue authoring tools that support cooperation between health coaching experts and system developers; investigates tailoring of coaching strategies that determine the underlying long-term course of coaching conversations; introduces a five-step tailoring process and a topic model to support automatically tailoring coaching conversations on the topic level; and evaluates a proof-of-concept implementation of such automatic topic selection in a micro-randomized trial.

The final chapter discusses the main findings and conclusions following three themes: 1) content and system design, 2) tailoring content and conversations, and 3) evaluation of tailored content. It concludes that content should be carefully constructed and reported, that tailoring approaches should be combined, and that evaluation of tailored applications remains complicated due to the many options for tailoring and factors of influence in long-term daily life situations. The second part of the chapter then discusses considerations for future work for five themes: safety, verification and validation; autonomy and trust; social interaction; input and output modalities; and open science.