This article describes methodological processes focusing on developmentally appropriate, creative data collection strategies for use with children and adolescents, illustrated from data-based research. The research reported includes adolescents' understanding of physical activity and engagement in designing a computerized questionnaire, adolescent decision making and consent to psychiatric treatment, social skills focus groups for children with behavioral disorders, and development of a longitudinal intervention study to improve the physiological-functional-psychosocial status of children with cystic fibrosis from three qualitative studies of children and adolescents with cystic fibrosis. Use of developmentally appropriate strategies is critical for successful research, contributing to our understanding of the world of children and adolescents.