Rethinking computer science education from a test-first perspective

Abstract

Despite our best efforts and intentions as educators, student programmers continue to struggle in acquiring comprehension and analysis skills. Students believe that once a program runs on sample data, it is correct; most programming errors are reported by the compiler; when a program misbehaves, shuffling statements and tweaking expressions to see what happens is the best debugging approach. This paper presents a new vision for computer science education centered around the use of test-driven development in all programming assignments, from the beginning of CS1. A key element to the strategy is comprehensive, automated evaluation of student work, in terms of correctness, the thoroughness and validity of the student's tests, and an automatic coding style assessment performed using industrial-strength tools. By systematically applying the strategy across the curriculum as part of a student's regular programming activities, and by providing rapid, concrete, useful feedback that students find valuable, it is possible to induce a cultural shift in how students behave.