The courses and programs of study college students select are the building blocks of academic progress and degree completion. Yet academic selection is a complex phenomenon, especially under elective curriculums, common in the US, which present students with serial selection tasks as they move through academic time. This paper reviews prior work in this domain, notes its assets and limitations, and provides a conceptual framework for theorizing, observing, and modeling academic selection. We offer the idea of selection architectures: the scale and arrangement of selection tasks students must complete in order to obtain degrees. To fully understand and model academic selection, researchers must consider (a) the character of specific selection architectures; (b) how students navigate these architectures; (c) and how architectures are maintained and changed by academic planners. A cumulative science of academic selection can inform the design of postsecondary programs to improve transparency, efficiency and equity in course/program selection and degree completion.