Mental health activities conducted by patients between therapy sessions (or "therapy homework") are a component of addressing anxiety and depression. However, to be effective, therapy homework must be tailored to the client's needs to address the numerous barriers they encounter in everyday life. In this study, we analyze how therapists and clients tailor therapy homework to their client's needs. We interviewed 13 therapists and 14 clients about their experiences tailoring and engaging in therapy homework. We identify criteria for tailoring homework, such as client skills, discomfort, and external barriers. We present how homework gets adapted, such as through changes in difficulty or by identifying alternatives. We discuss how technologies can better use client information for personalizing mental health interventions, such as adapting to client barriers, adjusting homework to these barriers, and creating a safer environment to support discomfort.

Psychosocial therapies play a crucial role in effectively treating anxiety and depression. An integral aspect of these therapies involves setting goals that clients engage in outside therapy, known as therapy homework or between-session goals. Yet, clients overwhelmingly do not complete between-session goals. This study explores mental health therapists' and clients' challenges in collaborating to set and manage engagement with between-session goals and discusses how technology could better support them. We interviewed 13 therapists and 14 clients about their experiences with between-session goals. We identified therapists' needs for information to support their clients, challenges in collaboration, and how technology can support client-therapist collaboration. Therapists need in-the-moment information about clients' engagement with goals to inform their decision-making. Clients may feel reluctant to share information due to a lack of trust, embarrassment, or not knowing what to share. Clients could use technology to asynchronously communicate about sensitive topics with their therapists. Technologies could facilitate gathering in-the-moment data that supports client-therapist collaboration on goals.

Goal setting is critical to achieving desired changes in life. Many technologies support defining and tracking progress toward goals, but these are just some parts of the process of setting and achieving goals. People want to set goals that are more complex than the ones supported through technology. Additionally, people use goal-setting technologies longitudinally, yet the understanding of how people's goals evolve is still limited. We study the collaborative practices of mental health therapists and clients for longitudinally setting and working toward goals through semi-structured interviews with 11 clients and 7 therapists who practiced goal setting in their therapy sessions. Based on the results, we create the Longitudinal Goal Setting Model in mental health, a three-stage model. The model describes how clients and therapists select among multiple complex problems, simplify complex problems to specific goals, and adjust goals to help people address complex issues. Our findings show collaboration between clients and therapists can support transformative reflection practices that are difficult to achieve without the therapist, such as seeing problems through new perspectives, questioning and changing practices, or addressing avoided issues.