As a non-participant observer of a Teaching and Learning Research Initiative (TLRI) on children's storytelling, I explored children's understanding of research involving them, including their rights to consent, assent and dissent to participate. In this case study of Timmy's participation in research, I show how Timmy's researcher sought and affirmed his ongoing right to agree to participate in data gathering, or not. The data show that Timmy's understanding of his part in the research process was limited to parts of the research process. I conclude with a discussion of some consequences for research that supports children's participation rights.