Debugging: clarify failures

[amyjko]

Something I want to learn more about is Failures. The article separates failures from defects and faults by defining failures as: "a failure is a program behavior that is inconsistent with a program’s requirements. Failures are what we report in bug reports, what we often mean when we say “bug”, and ultimately what matters in the world, as program behavior is what programs do to the world" But despite giving this explanation, are there any other examples that can be used to distinguish failures from different bugs? Can failures range in severity from minor to severe, are there different ways to categorize different failures?

The article did a good job of explaining different debugging techniques, however the types of bugs (defect, fault, failure) were not tied back in when discussing the techniques. For example, are certain techniques better when dealing with defects but not failures, or does the type not effect which debugging technique is best to use?