Becoming a Testing Expert


Achieving expertise as a tester is a progressive journey. It helps to have a vision to guide your efforts. James Bach, a well-known name in software testing, shares his vision of expertise and provides a testing challenge for those aspiring toward expert status.

One of the paradoxes of hiring good entry-level testers is that some of the very people who are good at finding fault, find so much fault with themselves that they assume they are unqualified to be testers. We never see their resumes.

What we're left with, a lot of times, are candidates who are overconfident in their ability to find good bugs. The same holds true for conference speakers. I've met dozens of interesting people at conferences who have helpful advice and interesting experiences. But when I encourage them to get up and speak or to write an article, most of them say, "Well, I'm not an expert. I don't know the right answers. I haven't read all the books." Valuable insight thus remains bottled up inside the self-skeptical minds of many excellent testers, while too many people who do speak and write could stand to put their ideas through a little more testing.

I fancy myself a good tester. I could be wrong about that. Ask me in another fifteen years. What I know as the truth is that I am working toward expertise. How do I keep myself moving along that path? A vision helps. For all of us who aspire to expert status, we need a vision of expertise that stirs our hearts and sets a high standard, yet seems achievable in one lifetime.

A Personal Vision
I can test anything, under any conditions, in any time frame…

This may be a nice start. The problem is that it's not achievable. For instance, if people don't like me, or have a different view of what good testing means, then I will not be able to perform well on that project. If I don't understand enough about the technology I'm testing, my test design will be weak. If I don't try very hard, I will do mediocre work. So, this vision needs a few qualifiers.

Let's add:

…to a degree relative to…

  • my standing in the local process culture
  • my knowledge of the relevant technology
  • how much I want to succeed

That goes a little way toward making the vision more realistic, but it still seems overreaching. Where is the quality standard? After all, I can do anything, as long as I'm allowed to do it badly. How could you be true to this vision, and test well, if someone asked you to test a nuclear power plant in five minutes? To deal with that problem, let's add some more specific assertions about expertise:

…such that…

  • I perform at least as well as another expert would
  • I deliver useful results in a usable form
  • I choose methods that fit the situation
  • I make appropriate use of available tools and resources
  • I collaborate effectively with the project team
  • I can explain and defend my work
  • I can advise clients about the risks and limitations of my work
  • I can advise clients about how my work could be even better
  • I faithfully and ethically serve my clients
  • I become more expert over time

Now the vision is within the realm of possibility, even though it's quite a challenge.

In this view of expertise, "I can test" really means "I can perform well as a tester." This is measured by a human standard: the behavior of the best experts we can find. With that standard in mind, how would experts react to the problem of testing a nuclear power plant in five minutes? Answer: the people I most respect would begin by invoking one of the great tools of testing-questioning the constraints of the problem. The best five minutes of tester behavior, I think, would be to ask "What's going on here?" or some question like that. Or in this particular case, perhaps, "Are you out of your mind?" which highlights the absurdity of the constraints.

Practically speaking, embracing a vision of the best standards is to make a habit of looking at any product and wondering "How would I test that? What if I had to test it without a spec? What if I had to test it in half the time?"

With that in mind, here's a testing challenge for you. Six years ago, I wrote a little Windows program for use as an exercise in my testing class. I still use the program today. I give students fifteen minutes to test it. If I gave you only three minutes to evaluate it and tell me if it's good enough, what would you do? I can think of four different answers that an expert tester might provide…

Think about it. If you want my answer, see

User Comments

soumendra barik's picture
soumendra barik

Hi Mr Bach,

I have been a Manual Black Box tester for more than two years. My company has never required me to work as a automation tester. From a career point of view is there any future is pursuing Manual testing or should I change my focus to automation testing ?

May 29, 2013 - 9:05am
Adeel Shoukat's picture
Adeel Shoukat

Hi James you are doing a good job in testing can you please tell uss a little bit about automation testing and its basic concepts.As i am new in automation testing and need some expert guidance.



June 16, 2011 - 5:46am
rahul rohitashwar's picture
rahul rohitashwar


I am a beginner in testing field.So for exploring my knowledge i need some help from u.Can u suggest some book to get better knowledge

With Best Regard

Rahul Rohitashwar

June 26, 2011 - 1:17pm
Rajdeep Singh's picture
Rajdeep Singh

Hi James,

I have read all the articles on your website "'

I really appreciate the knowledge that you have shared on that site. It is really useful to people who wants to adopt RST in their firms

August 6, 2012 - 7:52am

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