Literacy researchers often include young children in the research process. Yet discussions about the complexities of gaining and keeping assent are often missing in research reports. In this paper, we report on our attempts to make the assent process, a typical requirement for Institutional Review Boards, an educative experience for children in a critical literacy Kindergarten classroom. We asked: When assent is treated as a text to be read, revisited, interpreted and negotiated, what meanings are made by young children? We designed research lessons and collected artefacts of students' learning, including interviews. Our analysis traced children's developing recognition and critical analysis of concepts such as voluntary participation, understanding of procedures, confidentiality, benefits and risks of the study, and the right to ask questions. We found that when assent is treated as an educative process, particularly in the context of critical literacy education, young children learn and make meaning about their rights and responsibilities as participants. We present evidence of meaning-making, transfer and voluntariness of each ethical concept. Implications for literacy research with young children are discussed.