Scaling up Functional Programming Education: Under the Hood of the OCaml MOOC

Co-written by Benjamin Canou (OCamlPro) and Gregoire Henry (OCamlPro).

This article describes the key innovations used in the massive open online course 'Introduction to Functional Programming using OCaml that has run since the fall semester of 2015. A fully in-browser development environment with an integrated grader provides an exceptional level of feedback to the learners. A functional library of grading combinators greatly simplifies the notoriously complex task of writing test suites for the exercises, and provides static type-safety guarantees on the tested user code. Even the error-prone manual process of importing the course content in the learning platform has been replaced by a functional program that describes the course and statically checks its contents. A detailed statistical analysis of the data collected during and after the course assesses the effectiveness of these innovations.