Individuals can infer what others are likely to know by clustering knowledge according to common goals, common topics, or common underlying principles. Although young children are sensitive to underlying principles, that manner of clustering might not prevail when other viable means are presented. Two studies examined how a sample of 256 children at ages 5, 7, 9, and 11 decide how to generalize another person's knowledge when goals, topics, and principles are put in conflict. In both studies, younger children preferred generalizing according to goals and topics, whereas older children preferred clustering based on principles related to disciplines. The most naturalistic ways of envisioning how knowledge is clustered in the minds of others therefore seems to change significantly during the elementary school years.