Reverse Engineering
Reverse engineering (RE) is an idea of ancient origin; the name was coined by Davidson and Lynch (2002), but they are the first to admit that all they created was the name. RE is an analytical process of test creation that begins with an actual test question and infers the guiding language that drives it, such that equivalent items can be generated.
It is a very good idea to stress an evolving spec by trying to write a new item during our reverse engineering. This helps us to understand better what we are after.
Perhaps all supposed spec-driven testing is actually a form of reverse engineering: we try to write a blueprint to fit item or task types – archetypes – that are already in our experience (Fulcher & Davidson, 2007).
There are five types of RE, and the types overlap (Fulcher & Davidson, 2007):
- Straight RE: This is when you infer guiding language about existing items without changing the existing items at all. The purpose is solely to produce equivalent test questions.
- Historical RE: This is straight RE across several existing versions of a test.
- Critical RE: Perhaps the most common form of RE is Critical RE.
- Test Deconstruction RE: Whether critical or straight, whether historical or not, provides insight beyond the test setting.
- Parallel RE: In some cases, teachers are asked to produce tests according to external influences, what Davidson and Lynch (2002) call the “mandate”.