“Can you list at least 2 test cases for testing a blank sheet of paper?” – This was a question listed on another LinkedIn discussion. There are over 80 comments (so far) that appear to be split right down the middle.
Half of the commentor’s automatically started to list out various test cases… (Some of them rather bizarre and unjustified):
- “Check that it is blank”,
- “Check that it is paper”,
- “Check the colour”,
- “Test that you can write on it”, and even
- “Check that its glossy”
I mentioned that some of these tests are “unjustified”, simply because they are based on massive assumptions about the customer’s need for the blank paper.
I have the opinion that you need to ask more questions before committing to any test cases. You might think: “you can check that the ‘paper is blank’ and ‘that it is paper'”… But can you really?!? How do you know what “blank” actually means to the customer? How do you know what “paper” means to the customer?
What I mean by this, is that “blank” could mean that the paper should have nothing on it, but it could also potentially be branded letterhead paper, with the company’s logo on it, but should simply have no printed text on it. And “paper” could mean a plain sheet of copy paper, or it could really mean tracing paper, or wrapping tissue, or wallpaper, etc.
How can we test that the “blank paper” is “blank” and that it’s “paper” if we don’t know what the customer’s requirements are for the blank paper actually are?
The only way to supply suitably accurate test cases in this instance is by investigating more about the product and its purpose. You firstly need to determine what the paper will be used for, e.g.:
- Is the blank paper going to be used in a printer to print on?
- Is it blank paper that will be folded up and used as a door stopper or to cure a wobbly table?
- Is it blank paper that someone will write on with a pen?
- Is it blank paper that will be used as toilet paper?
- Or is it blank edible sugar paper that will be used on a fresh batch of cupcakes?
Only when we know what the customer’s intentions are for a product, will we be able to adequately begin to list appropriate basic test cases for the product. I say “basic” as you will not be able to list ALL possible test cases… This is because you do not know what the customer’s expectations are of the product that they need. Knowing what the product is going to be used for will allow us to stem more questions in order to learn more about the expectations that the customer has of the product, e.g.:
- Does the toilet paper have to be of a certain thickness or have a pattern on it?
- Should the sugar paper need to have any specific flavour such as vanilla?
- Should the printer paper be glossy or matt, and of a certain thickness?
- Does the paper to be written on need to work with a special type of pen, such as a fountain pen or marker pen?
- Should the blank paper be of a certain colour?
Once we know more information, with a better understanding of what the product should be/do, then we can then supply accurate and suitable test cases.
And with a question such as: “list test cases for blank paper”, the best way to gain the knowledge needed of the product in order to be able to create suitable test cases is to ask questions.