l. The symptom and the cause may be geographically remote. That is, the
symptom may appear in one part of a program, while the cause may actually
be located at a site that is far remove Highly coupled components
(Chapter 8) exacerbate this situation.
2. The symptom may disappear (temporarily) when another error is corrected.
3. The symptom may actually be caused by nonerrors (e.g., round_off
inaccuracies).
4. The symptom may be caused by human error that is not easily traced.