September 4, 2010

Testing is a Box of Many Colors

not actually me

During my first ever interview for a QA position, I was asked if I knew what Black Box Testing was.  Not knowing anything at all about QA, I admitted that I wasn't sure.  But I had heard the term Black Box before, so I described that, and how I thought it might apply to testing.  Apparently it was a good enough answer, since I ended up getting the job. copyrightjoestrazzere

At some point in time, I heard the term White Box Testing.  Knowing what Black Box meant, and the context of how the new term was used, I understood the meaning.

Since then, I've seen a virtual rainbow of invented terms.  And recently, Rob Lambert over at the Software Testing Club asked "How many different colour boxes are there?"

Among the responses he got were:

  • Black Box Testing
  • White Box Testing
  • Gray (or Grey) Box Testing
  • Clear Box Testing
  • Glass Box Testing
  • Pink Box Testing
  • Red Box Testing
  • Yellow Box Testing
  • Green Box Testing

To me, anything much beyond Black Box and White Box is foolishness.  I get the distinction between the two without much thought.  But venturing beyond that almost always requires further company-specific interpretation.

Do we use Gray Box Testing?  Perhaps.  It depends on how dark or light a shade of Gray you mean, I suppose.  Red Box Testing?  I don't know.  Purple or Brown?  I might have done that once by accident.

Can we as professionals refrain from constantly inventing new, dare I say "colorful", terms?  Probably not.  But as Michael Bolton over at DevelopSense writes, the final test of a metaphor or heuristic is "Is it useful?"  I don't see much use for this rainbow of terms, but perhaps you do.

"When I use a word," Humpty Dumpty said in a rather scornful tone, "it means just what I choose it to mean - neither more nor less."  I think I may have interviewed with Mr. Dumpty once or twice.

See also:

My name is Joe Strazzere and I'm currently a Director of Quality Assurance.
I like to lead, to test, and occasionally to write about leading and testing.
Find me at


  1. Most people don't believe me when I tell them that I once did Violet Box Testing. I really did it. The box I tested was colored Violet :)!!!

  2. When I first read this comment I read it as Violent Box Testing.

    Now who among us hasn't done that?