Wednesday, July 28, 2010

Repsonse: on How many test cases by James Christie

Somehow the question about how many test cases is so important for "important" people. As if they are getting paid by numbers instead of valued for delivered value. Somehow a false trust is derived from figures. People rely on numbers and assume that number of test cases represents good quality. This seems so obvious the way of doing.

The posting of James Christie triggered me to answer using my weblog.

I value the blog posting of But how many test cases? written by James Christie by its content in relation with his defined context. This context is lost when you translate it to numbers. Below you will find several attempt to make a good posting valued wrong.

Example 1:
Imagine that your blog posting is rated by the number of letters. In your posting you use about 5534 characters. Telling the same story using twitter you need over 40 tweets. Does this show value? It seems that one post in a blog provide more value then one tweet, although the tweet which pointed me to that blog was also very valuable. So is 1 more then 40?

Example 2:
Or what about the coverage of letters. You used all letters of the alphabet, this means your coverage is 100%, does this provide some information about the quality of your posting?What about assigning numbers to it?

Impressive usage of the letter “e” based on numbers it is far most the extensive used letter. Does this provide information? I don’t think so, Perhaps the letter “e” should be used more often, perhaps in relation with other letters. Even this way of thinking is wrong. It doesn’t tell any thing about the context.

Example 3:
What about visualizing the numbers. Below you see a snap shot I you look only at the numbers mentioned in his blog.

I also left some noise in it. The (con)text is now removed.

What does it value now? What information can be obtained? Perhaps the 100.000 mentioned in the text is impressive

Is it correct to drive our testing on numbers? Is it useful to explain coverage in terms of test cases executed? Is the weblog of James in the based on my examples valid and good? The numbers are clear and proven? Are you counting the time?

I compliment James with his blog. A lot of time is spend to "proof" something which is explained incorrect. Wrong questions are asked.

Tuesday, July 27, 2010

What to learn from puzzles

Here a brief posting to express my thoughts what skills can be learned from playing with puzzles. Michel Kraaij triggered me to share my thoughts about this using twitter were he is involved with a discussion with James Bach. Somehow there is a 140 character restriction and also for him this posting.

As I'm no part of their discussion I will not summarize their ideas. The main idea to trigger Michel is to tell him about my idea "ppl become better in solving the puzzle, only they got trained in other skills which helps them solve."

With this statement I intended to express my thoughts that there are other things people learn from playing with puzzles and even repeating them. It is not only the notion of remembering the position of certain pieces.

In my opinion the following things can be learned:
- position of pieces
- shape of pieces
- how does pieces of for instance jigsaws fit Initially

You can also extend the perception of puzzles. Initially I would think also in terms of jig-saws, this might be disadvantage of my native language (in the Netherlands I was trained to call jigsaw puzzles and forgot about not all puzzles are jigsaws)

So what else can be learned from playing with puzzles? To understand this you can look at the outcome: "A puzzle is solved or is not solved."

Not solving is not a failure; even in the process playing with the puzzle you might have learned things.
What can be learned?
- new approaches to solve a puzzle
- new languages
- other visions
- different approaches.
- looking in patterns to jigsaws
- identify differences between the puzzle which is being solved in comparison with puzzles previously solved
- awareness you have gained new information
- ability to use that new information to use in different approaches
- new attitude to approach things like under time pressure, too less information etc

Perhaps the main result of playing with puzzles is the creation of awareness of the persons capability/ability to identify differences in environments and to use different ways to approach "complex" situations with the available knowledge. The person might teach himselve about the sufficiency of information/skills to perform the task or the need more training/guidance/information. If a person learns when to ask for help, a valuable lesson is learned.

The main idea is that there is more to learn from puzzles then repetition.

@Michel, perhaps we should meet each other again to evolve our thinking about this.

Tuesday, July 20, 2010

Failure is also human behaviour

Did you ever wonder if a failure could be avoided if skilled people were participating in your project? Did someone ever doubt the developer not able to deliver good code and the tester to provide well executed test scripts? Was the team you were working in a highly motivated team and bugs were delivered real time? Was the trust and believe missing towards the application and the people although everyone did a good job, was motivated, made and kept their promises followed the process and still issues were found on a system which should be reliable?

Perhaps you have not been in a situation like that.

How often did you sit down in the lunchroom of your company? Do you sit down your own seat? Was the seat in a particular corner of the room? Or did you sat on all chairs during the years?

I have been in such a place for over 2 years. There are perhaps over 100 seats and most and during the years I sat on almost every one of them. Here is the trick; I’m not able to tell for sure as I have my favourite spots. It doesn’t matter. The issue here is that I perhaps missed some chairs or perhaps not as result of my behaviour. It is in human behaviour to find the safest spots. For some people this is near a window, near an escape door, some people like to sit with their back against the wall. Some people are not aware of the options and others don’t care.

I’m sure there are other behaviours on this. In my opinion it is important to acknowledge that human behaviour influence the outcome. Often the reason behind that behaviour is not noticed or measured. I think it is not mandatory to measure everything. Though it is important for a tester to be aware of differences in human behaviour and learn to defocus to see better which relations are created between human and its environment.

Failures are not only technical, therefore the tester needs more skills.