The purpose of this study was to characterize the prior conceptions of molecular structure that organic chemistry students expressed as they learned to interpret nuclear magnetic resonance spectra, and to describe the problem-solving strategies that students employ as they determine molecular structure. The two questions that frame this study focus on the development of scientific concepts and problem solving strategies. Findings indicate that students generate two-dimensional illustrations of molecular structure as a default mode and that computer modeling holds promise in helping students overcome misconceptions about molecular structure. (Contains 37 references and 15 tables.) (DDR)