Recent experimental research highlights young children's selectivity in learning from others. Little is known, however, about the patterns of information that children actually encounter in conversations with adults. This study investigated variation in parents' tendency to focus on testable evidence as a way to answer science-related questions (e.g., causes of climate change, extinction of species) and asked whether this is related to children's own use of evidence in conversation. Parents read a science-themed book with their 4- to 8-year-old children. Guided by D. Kuhn's framework of epistemological stances, we coded (a) parents' expressions of epistemology-related information (e.g., using evidence to reason about an opinion, appealing to statements of fact that do not need evidence, or pointing out that knowing for sure may not be possible) while discussing four science-related topics and (b) children's comments about evidence for two different science-related topics. We found variation in parents' expressions of epistemological information by children's age and gender for particular topics. Also, parents' expressions of evaluativist epistemology (expressing the value of reasoning with evidence) were correlated with children's talk about evidence. To the extent that children experience different conversational environments, they may seek different types of answers to questions, become familiar with different ways of thinking about "knowing," and develop different strategies for being selective about learning from the testimony of others. (Contains 1 table and 3 figures.)