  In today's connected society, self-tracking technologies (STTs), such as
wearables and mobile fitness apps, empower humans to improve their health and
well-being through ubiquitous physical activity monitoring, with several
personal and societal benefits. Despite the advances in such technologies'
hardware, low user engagement and decreased effectiveness limitations demand
more informed and theoretically-founded Human-Computer Interaction designs. To
address these challenges, we build upon the previously unexplored Leisure
Constraints Negotiation Model and the Transtheoretical Model to systematically
define and assess the effectiveness of STTs' features that acknowledge users'
contextual constraints and establish human-negotiated STTs narratives.
Specifically, we introduce and validate a human-centric scale, StoryWear, which
exploits and explores eleven dimensions of negotiation strategies that humans
utilize to overcome constraints regarding exercise participation, captured
through an inclusive storyboards format. Based on our preliminary studies,
StoryWear shows high reliability, rendering it suitable for future work in
ubiquitous computing. Our results indicate that negotiation strategies vary in
perceived effectiveness and have higher appeal for existing STTs' users, with
self-motivation, commitment, and understanding of the negative impact of
non-exercise placed at the top. Finally, we give actionable guidelines for
real-world implementation and a commentary on the future of personalized
training.
