So, I’ve been playing way too much Modern Warfare 3 (MW3) and I’ve noticed a new word that at first glance was a replacement for “bug”.  Players refer to “glitches” in the game where say a body will lie suspended in air even though they it fall to the ground.  It doesn’t stop the game, but it is not expected behavior.  Now I doubt that there was a requirement in the MW3 software development plan that stated, “All bodies, once shot, will fall to the ground.”  And they probably didn’t have a test case around it either.  But because it is a game based on reality, you notice when something deviates from reality.

In my graduate testing course, we had specific definitions for terms like faults, bugs, and errors.  But we never mentioned the word “glitch”.  The Software Engineering field needs to get ready for this term and to help that, I’ll attempt to define it.  Now the Oxford English Dictionary defines a glitch as a:

A surge of current or a spurious electrical signal (see quots.); also, in extended use, a sudden short-lived irregularity in behaviour.

Interestingly, it seems Astronauts used the term a lot.  Here is a quotation from John Glenn:

1962   J. Glenn in Into Orbit 86   Another term we adopted to describe some of our problems was ‘glitch’. Literally, a glitch is a spike or change in voltage in an electrical circuit which takes place when the circuit suddenly has a new load put on it.‥ A glitch‥is such a minute change in voltage that no fuse could protect against it.

I think these two pieces of information help define a software glitch.  One, it is short-lived and the application continues to run smoothly overall.  Second, it is very hard to reproduce and hence creating a test case for it is also inordinately difficult.  Third, because it is short-lived and doesn’t bring the system down, it is a possible siren of something more troubling going on, but it could just be a “one-time” thing.  Very similar to the movie “The Matrix” where Neo notices a “glitch in the Matrix” and it alarms the others because that usually means that the Matrix is being changed by the agents.  Although it could also just be deja vu (the glitch Neo saw).