Test cases for Pen / Pencil / BlackBoard

I have always been asked this question. Never was prepared. There are many variations to this question. But if we just spend a few minutes on this question we will be able to do a good job.

A book on Interviews says this way:

This problem is largely about understand the constraints: what exactly is the pen? You should ask a lot of questions to understand what exactly you are trying to test. To illustrate the technique in this problem, let us guide you through a mock-conversation.

Interviewer: How would you test a pen?

Candidate: Let me find out a bit about the pen. Who is going to use the pen?

Interviewer: Probably children.

Candidate: Ok, that’s interesting. What will they be doing with it? Will they be writing, drawing, or doing something else with it?

Interviewer: Drawing.

Candidate: Ok, great. On what? Paper? Clothing? Walls?

Interviewer: On clothing.

Candidate: Great. What kind of tip does the pen have? Felt? Ball point? Is it intended to wash off, or is it intended to be permanent?

Interviewer: It’s intended to wash off.

…. many questions later ...

Candidate: Ok, so as I understand it, we have a pen that is being targeted at 5—10 year olds. The pen has a felt tip and comes in red, green, blue and black. It’s intended to wash off clothing. Is that correct?

…

The candidate now has a problem that is significantly different from what it initially seemed to be. Thus, the candidate might now want to test:

1. Does the pen wash off with warm water, cold water, and luke warm water?

2. Does the pen wash off after staying on the clothing for several weeks? What happens if you wash the clothing while the pen is still wet?

3. Is the pen safe (e.g.—non-toxic) for children?

and so on...

Basically, testers need to make sure of all the requirements. We may start off my giving out 5 to 6 ways of testing / negative tests etc. But first of all make sure if you have got all the requirements. Ask all kinds of question and then you will be able to answer well and also not get stuck after giving out few test cases.

So what if there are no requirements? Sometimes we do find some crazy interviewer who just want us to stumble and fumble. Then just tell them the following.

Non Functional Test Cases :

• Test whether the object (a pen ofcourse) looks like a pen (obviously there must be some expected result by which u can compareb ans can say ,..yes this is a pen )
• Test Whether the pen can be gripped easily (the pen body must not be too thick or too thin)
• The Grip from where u hold the pen ,must be comforting to the Finger Tips
• The Grip does not makes you put more pressure while writing
• The look and feel must be good
• By looking at the refill you can say that , we can use since it has ink (smoke test case for pen , 'cos u can simply reject the product)

Functional Test Case :-

• Whether it writes on paper or not
• The ink flow is steady
• The alphabets written are smooth in curves (just checking the tip / ball of the nip)
• The nib doesn't tear the paper
• There is no overflow of the ink
• The ink on the paper is in same color as what we see in the refill
• The pen does not loose its twists .. (I donno how I can elaborate this though , The simple meaning is that the pen parts are not lossend apart)
• It can write on any other surface but the ball will be damaged ... (load test)

Performance and load

• How it performs when writing on Wet paper
• How it performs when writing on Rough Paper
• How it performs when writing on hand (we occasionally do that )