debugging

    The process of attempting to determine the cause
   of the symptoms of malfunctions in a program or other system.
   These symptoms may be detected during testing or use by real
   users.

   Symptoms are often caused by factors outside the program, such
   as misconfiguration of the user's operating system,
   misunderstanding by the user (see PEBCAK) or failures in
   other external systems on which the program relies.  Some of
   these are more in the realm of technical support but need to
   be eliminated.  Debugging really starts when it has been
   established that the program is not behaving according to its
   specification (which may be formal or informal).  It can be
   done by visual inspection of the source code, debugging by
   printf or using a debugger.  The result may be that the
   program is actually behaving as specified but that the spec is
   wrong or the requirements on which it was based were deficient
   in some way (see BAD).

   Once a bug has been identified and a fix applied, the program
   must be tested to determine whether the bug is really fixed
   and what effects the changes have had on other aspects of the
   program's operation (see regression testing).

   The term is said to have been coined by Grace Hopper, based
   on the term "bug".

   (2006-11-27)