Wednesday, September 14, 2011

"Checking is not Testing" GR-Testers recap 9/13/2011

I had a great time at the Grand Rapids Software Testers meeting last night.  The main topic was "Checking is not Testing" which inspired a great deal of lively conversation.

We gathered once again at Salvatore's in Grand Rapids.  We started on the deck but decided it was a bit to chilly and moved inside for the rest of the evening.  There was a great showing, with Wade coming all the way from Traverse City just for our event (really this time.)  Todd, Pete, Greg, Anita, Mrs. Walen, ??? (a delightful young lady, guest of Pete's but I can not remember her name), Rob, Mel and David were there too.  That is ten in all if you are playing along at home.

We ordered food and waited for later arrivals.  Starting our usual catchup time, it was a busy month.  Rob brought many entertaining stories from his trip to Chicago.  Pete brought news from CAST including this outstanding quote:

"Counting test cases to assess coverage is like using frequent flyer miles to see how much of the world someone has seen.  It doesn't work" -- Benjamin Yaroch  at CAST 2011

Captured by Mel at

The food arrived, it was excellent, perhaps even more so than usual.  We noticed that it was getting a little late, and discussed moving the main discussion ahead of the food for next month.  After eating and clearing dishes the main discussion ensued.

"Checking is not Testing"

We wanted to explore the similarities and differences in checking and testing.  Both activities has a place and are useful in the process of improving software but is one over emphasized, is one seen as a silver bullet and over used to try to solve problems it can not solve?

We started with a little activity you can try yourself at:

This is a little exercise to emphasize the point.  There is a big difference between checking and testing.  With pure checking to specification the calculator "works" that is it passes all of the "tests".  It is quite impossible to miss some of the glaring problems.  But.  If it was an automated test it surely would pass.  What if there were only a mechanism to indicate that the prescribed "tests" passed?  The result would be "Ship it!"  As facilitator of the activity I was accused of sounding a lot like a product manager , I took this as a compliment to my acting skills.  After running the prescribed tests checks, we really tested the calculator.  It was not hard to find problems, they were put there on purpose but what if this were a real product, with problems not so obvious?

After the introduction, a lot of really good discussion took place.  We talked about testing only to specification, the problems that arise, the ethical dilemma.  Can a professional tester test only to specification?  Should a professional tester test only to specification?   Can testing be automated?  What is the difference between checking and testing?  When is checking useful and when is testing required?  It was great discussion.  I encourage you to use these questions to seed future discussion.

Some of our observations were that testers do not have the narrow focus of the machine.  We see "what else happened" (the '5' changed color when the '8' is pressed.)  We discussed how testers try things that are outside the vary narrow test plan, what happens when I try the '6' (nothing.)  We talked about noticing things that are just plain wrong, there is no zero, the numbers are in a zig-zag pattern, the '9' is not styled and so on.  These are things that do not get tested with automated checks.

We talked about the value of automated checks.  With TDD and automated checks are useful to ensure the program works to specification.  Automated and scripted checks are also useful as a way of defining and checking on problems that have occurred in the past to see that they have not returned.  It is very important to recognize the limitations of automated check.

We discussed the terminology.  "Checking" vs. "Testing" these words are thrown around so loosely that it is easy to get confused.  It is understandable that people less interested in testing are confused also, they do not care of semantics, they want their bonus, they want it to work right, they want it now.  I think we must all bear the burden of educating those we work with on the proper terminology.  We must also present the value and limitations of checking and testing.  These words are deeply ingrained in the language, sometimes in a way that may be a little wrong.  "Unit Tests" are not tests.  "Automated Acceptance Tests" are not tests.  TDD may be better termed as CDD.  Hoping that these will be corrected in the language may be like hoping the talking head on the nightly news will learn the difference between "hacker" and "cracker" it just ain't gonna happen.

We discussed "Requirements" and testing to them.  We talked about how they are a mysterious moving target and that there quite often seems to be a stated or unstated requirement of "... and none of my existing data or functionality are harmed."  We talked about how this is the very essence of the argument for doing real software testing.

We shared some war stories.  Some involving real war.  A missile being tested (in front of top brass) failed.  Performance testing (not testing the performance of the product, showing the product off) running the product in such a way to "prove" it ready for shipment by carefully avoiding known pitfalls.  Pete shared the dismay he received when he developed a set of tests which were "missing" the "answers."  The expectation was that the answers were to be specified with the test.  Pete's point being that is not a test.  The tester should know when the output is wrong.  The tester should observe the other side effects of running the program.

Some of the group read and used portions of this article to seed the discussion:  we thank Michael Bolton (the software tester not that other guy, or the other other guy) for sharing this.

I had a really great time, judging by the time we wrapped up everyone else did too.

At the end of the evening we discussed topics and times for next month.  The tentative topic is "Education and Software Testing" it will be an interesting discussion for sure.  The time and venue are up for discussion.  The outside venue as Salvatore's is most likely out, and inside is a little difficult and we do not want to disrupt the other guests.  Be sure to watch the email list and check for details.

1 comment:

  1. Thanks for the write-up for those of us on the wrong side of The Pond