Think Like a Grandma and Find More Bugs !

Context:

Over the last few years of my experience as a tester in agile projects, I've experienced and observed this thing: whenever a new tester joins the team, he/she finds a bunch of new bugs. The rate of finding new bugs gradually decreases to normal level as the new tester spends more time in the team.

While I agree that I've overly generalized this, none the less it's a pattern that you can't ignore.

So I gave it some thoughts, and came up with this theory :-)

Think like grandma, find more bugs !

Let me brief on this a bit.

So, ever seen Grandma using the internet? Double clicking on links, opening a new instance of browser for each page and clicking on every ad that's on a web site, etc?

In similar lines, that's very much what a new tester does on application under test (AUT).

Initially when a new tester joins the team, his/ her understanding of the project is minimal. There's no 'acquired knowledge', no clue on how things should work. This leads to a set of new test scenarios which weren't thought of before. Hence the chance of finding new bugs increases.

This is all well, but over the time, the new tester becomes 'old, experienced' member of team. A lot of new knowledge, ideas on how things should work and ignorance towards 'non-conventional' scenarios develop. Me thinks this leads to a pattern where tester is worried only about the 'acceptance criteria', and chance of finding new bugs decreases.

Still with me? :P

So I spoke about this thought in an internal training in ThoughtWorks, while the idea it self isn't ground-breaking, there were a few questions.

How do we think like a newbie (Grandma) after spending considerable time in a project?

I think while it is a must have skill for an excellent tester to learn new things very quickly, I also demand that a good tester must be able to 'unlearn' things easily as well. This doesn't take much effort if you ask me. Just a constant reminder to yourself about ignoring knowledge of the AUT should do the trick.

Every time I take a new story to test, I tell myself that I am a brand new user who hasn't got a least idea what AUT should do. While it sounds foolish, also time consuming, it helped me a lot to find new test scenarios and hence, bugs.

Well, not every user is a Grandma user, isn't it?

Of course not. But for every level of proficiency in the AUT, there is a grandma level. What I mean is, your user might be a technically sound sysadmin, but there is a beginning for every one, isn't it? If your user is a well trained user, think yourself as a user who just came out of a 3 day theory course on how to use the system.

There is a Grandma level for every level of user. Just pretend you are one of them.

So, have you started using your AUT as a Grandma yet?

:)