In this module, we derived tests based on the structure of our programs. This means that we basically followed every control flow.

One way to devise tests is to not only look at control flow, but also at data flow. In other words, we could follow the variables of our program, and how one syntactic element can affect the computation of another. We call it data flow testing.

We do not cover data flow testing in this course. However, if you are curious about it, we suggest you to read Chapter 13 of Pezzè, M., & Young, M. (2008). Software Testing and Analysis: Process. Principles and Techniques, 4-6.