For my doctoral research, I will be conducting two parallel qualitative studies using interviews: one with persons with intellectual and developmental disabilities, and the other with family caregivers of persons with intellectual and developmental disabilities. I will be interviewing both populations about decision-making about a specific health-related topic. I am having difficulties determining a sample size for my dissertation proposal. Qualitative methods books do not specify a sample size, but rather speak of data saturation. However, as this research is time limited, I do not know if it will be feasible to gather data until saturation. I am therefore encouraged to specify a specific sample size that I aim to attain. Based on your experiences, do you have any recommendations or literature to share on the topic? Thank you kindly!