Chronically ill children are a vulnerable group for participation in clinical research. Available research on children's and parents' understanding of the consent process and research participation has been based on the assumption that the amount of information and level of comprehension influences whether they participate in research. Researchers and ethicists acknowledge that knowledge isn't the single determining factor, yet few have investigated what other factors influence the decisions of mothers and their chronically ill children. Therefore, it is crucial that we know more about the experience of chronically ill children and their mothers in research; specifically how they experience and understand assent and consent processes at initial enrollment and throughout the duration of a study; and what facilitates and impedes their active participation. The four specific aims are to: 1. Ascertain ethical concerns, process and meaning of mothers' informed consent and their children's assent to participate in clinical research; 2. Describe mothers' and their children's understanding of the clinical research in which they are involved; 3. Explore sociocultural influences on mothers' and children's willingness to become involved and continue participation in clinical research; 4. Describe structural factors mothers and their children identify that facilitate or impede assent, informed consent, recruitment, retention, and satisfaction in clinical research. In-depth interviews will be used to obtain the perceptions of mothers and their chronically ill children with diabetes, cancer, or sickle cell disease, and bone marrow transplant candidates. These four conditions were targeted in order to achieve heterogeneity of illness severity, treatment complexity, research experience, and cultural expectations. The sample will consist of: a) 75 chronically ill children age 9 to 18 years, who are enrolled in a clinical research project, and their mothers, b) 25 chronically ill children and their mothers who withdrew from research, and c) 25 mothers with chronically ill children who declined to enroll their children in research. Additional data related to characteristics of the child, illness, family, and research protocols will be obtained from the medical chart and the IRB consent form. Qualitative content analysis, matrix analysis and narrative analytic techniques will be the primary means of analyzing the data.