  Writing and argumentation are critical to both professional physics and
physics education. However, the skill of making an extended argument in writing
is often overlooked in physics classrooms, apart from certain practices like
lab notebooks or mathematical proofs. Computation is also critical to both
professional physics and, increasingly, physics education. In recent years we
have begun to develop a class of assignment, known as a computational essay, to
both leverage the creative affordances of computation and help students build
their argumentative writing skills. Computational essays are a type of essay or
report that combine text and code to express an idea or make an argument,
usually written in notebook software. In this article, we describe the
motivation and philosophy behind computational essays, as well as initial
results from a pilot implementation in an introductory undergraduate
electricity and magnetism course.
