A fundamental goal in the study of human cognition is to understand the transfer of knowledge. This goes hand-in-hand with the translational goal of promoting such transfer via instructional techniques. Despite a rich history of research using the analogical problem-solving paradigm, no study activity has been found to produce a robust rate of successful spontaneous transfer--even when the test is immediate. We propose the category status hypothesis as an explanation of the difficulty of transfer and as motivation for a novel approach to promoting transfer. We report a set of experiments evaluating a category construction technique based on a sorting task. In Experiment 1a, we found category construction to be significantly more effective than the "gold standard" of schema abstraction through comparison of 2 analogous cases. In Experiment 1b, we explored a variation of the category construction technique that did not reliably differ in effectiveness from comparison-based schema abstraction--we also verified that both study tasks were superior to a baseline task of separate summarization of 2 cases. In Experiment 2, we conducted a replication of the initial design with higher power and confirmed the significant advantage for category construction over schema abstraction via comparison. In Experiment 3, we compared category construction to an information-consistent reading comprehension control to evaluate competing interpretations of the category construction advantage found in Experiments 1 and 2. We discuss theoretical and applied implications of these findings.