The article begins by defining e-learning as the use of technology for teaching and learning.  Noting that there is no unified theory of e-learning, this article reviews the major theoretical frameworks to date—behaviorism, cognitivism, constructivism, digital media theory, and active learning theory—to suggest a common sphere of interests and a common vocabulary that differentiates it from traditional modes of learning.  The article then turns to a practical case study of e-learning, a MOOC on the Coursera platform created by the American Museum of Natural History in New York City. The case study demonstrates both how learning theory afford a template to guide MOOC creation, and how testing can reach beyond content assessment mastery to offer a laboratory for e-learning study.