The learning triangle described by Black, Wilson, and Yao (this issue) offers a powerful vision for improved student learning. Learning theory clearly plays a central role in the construct-centered approach presented by the learning triangle. But the assumption of such an important role requires Black et al. to devote corresponding care to the description of the learning theory and the articulation of the learning theory with other components of the triangle. The work by Black et al. is groundbreaking so given the originality the author is not surprised that they have left the learning theory underspecified for the support of the development of curriculum, pedagogy and assessment. In this article, the author reviews how the learning theory may be underspecified and the consequences of underspecification for the articulation of the learning theory with other components of the triangle.