Research on high school students using the Perry scheme (progressing from dualism to multiplicity, contextual relativism, and dialectic reasoning) suggests gifted students are at least one stage ahead of their agemates. While most students are grasping the notion of unanswered questions, gifted students are seeking structures to help them explain ambiguous realities. Problem-based learning offers a promising structure to support advanced epistemological reasoning. (15 references) (MLH)