Common Testing Thumb Rules Recommended by Testing Experts
Experts create rules of thumb to make an educated guess during their decision making process.
Such thumb rules are also called “Heuristics”. The word heuristic had originated from Greek, with a meaning “Serving to Discover.”
Experienced testers collect and share testing heuristics that improve the quality of their guesses. A good set of heuristics helps us generate tests very quickly.
Following are few examples of thumb rules that are quite helpful to the testers:
1) Test at the boundaries: Boundaries are more likely to reveal ambiguities in the specification.
2) Test every error message: Error-handling code tends to be weaker than mainstream
3) Test configurations that are different from the programmer’s: The programmer will already be biased toward making sure his own configuration works.
4) Run tests that are annoying to set up: Easy-to-set-up tests are more likely to be performed, all other things being equal.
5) Avoid redundant tests: If a test is truly duplicating another test, what new value is it giving you?
To use heuristics wisely, remember one thing: There is no wisdom in heuristics. The wisdom is with you. All the heuristic does is make a suggestion for your consideration. Blindly following heuristics that you don’t understand is not good testing practice. As you collect heuristics, try to understand the reasoning behind each one and the conditions under which it’s more or less likely to work.
Conclusion: Heuristics are not guaranteed to lead to the right answer or the best answer, but they are useful nonetheless.
Reference: Notes from Lessons Learned in Software Testing by Cem Kaner