Do children think that adult knowledge subsumes or only partially overlaps child knowledge? Sixty-four 4- and 6-year-old children were asked either whether a child and an adult know the answers to questions tapping adult- and child-specific knowledge (Experiment 1) or to whom each question should be addressed (Experiment 2). Children were also asked directly about the existence of child-specific knowledge. The experiments provided converging evidence that beliefs about child-specific knowledge are relatively limited among 4-year-olds but become well articulated by age 6. The findings contribute to understanding the development of children's beliefs about the relation between knowledge and age. (Contains 1 table, 5 figures, and 2 footnotes.)