Background <p>Adolescence is a critical developmental period characterized byincreasing independence, functional autonomy, and participation across lifedomains. Despite the importance of supporting adolescents in reflecting ontheir functioning and identifying meaningful goals, few adolescent-centeredtools enable self-assessment of functional autonomy and participation inengaging, digitally accessible formats. This study aimed to develop Take PART(Participation and Activities Rating for Teenagers), a computerized assessmentof functional autonomy and participation, and evaluate its usability.</p> Methods <p>The development of Take PARTwas conducted in two phases. Phase 1 focused on content generation and platformdevelopment using adolescent-reported activities, expert review, and auser-centered design process. Activities were organized into five life domains:self-care; daily activities at home and in the community; academicparticipation; work and volunteering; and leisure/social participation. Phase 2evaluated usability among 119 adolescents aged 12–18 years and 50 examinersusing the Post-Study System Usability Questionnaire (PSSUQ).</p> Results <p>Adolescent reports informed the development of a 65-itemassessment reflecting everyday participation and functional autonomy. Expertreview contributed to the refinement of the domains, items, and platformstructure. The final assessment supports individualized domain selection andcollaborative goal-setting. Usability findings indicated high levels of systemusefulness, information quality, and interface quality among both adolescentsand examiners.</p>