Sehee presented her full paper titled "Balancing Flexibility and Authority: Exploring Negotiation as an Interaction Strategy for Healthy Sleep Behaviors" at the DIS 2023 conference. This work proposed a new interaction concept of negotiating sleep hygiene goals between the sleep-supporting system and users, in order to promote users' sleep health. The study explored the potential and experience of negotiation through the experience prototyping method, in the form of improvisational role-playing. Based on the findings, the paper discussed the key characteristics and potential of negotiation interaction.