What are the attributes of a good tester—of a great tester? As every test manager knows, identifying the right people for a test team can be a struggle. In this column, Fiona Charles describes the qualities of mind she looks for in testers, and the interview questions she asks candidates so that she can evaluate how they think.
When I am staffing a test team, I look for testers with genuine skills—both testing skills and soft skills. Neither of these are straightforward or easy to find or evaluate, especially within the time constraints of an interview.
Beyond skills, I look for people with the right qualities of mind. For me, these include:
- Real enthusiasm for testing
- Analytical ability
- Creativity and problem-solving skills
- Critical intelligence: curiosity and skepticism
Paper qualifications—whether tester certification, post-secondary education, or testing courses—don't tell me anything about a candidate's possession of these qualities. I could learn something by asking the person to solve a puzzle, or to demonstrate how she would test a given piece of software, but I'm wary of a "one-size-fits-all" approach to evaluating people. We all need to be aware that different kinds of intelligence manifest in different ways. So I try to engage candidates in conversations that make them think. I work to move people away from their prepared answers to a conversational territory where they will reveal not only how they think, but also the qualities they truly value in doing the tester's job.
Gauge a Candidate's Feelings
I start with a couple of simple questions: Do you like testing? What do you like about it? Every candidate will claim to like testing, but the answers tell me whether or not it's worth going on with an interview. Some people light up when I ask those questions. Others don't show any spark at all. There is no one right answer. A passionate concern for users is valuable, even more so when it is coupled with glee in finding bugs and pursuing difficult clues. Good candidates display enthusiasm, searching curiosity, and a sense of joy Some people don't even seem to like software, let alone testing.
I also look for judgment in evaluating risk. I want testers who care about more than whether the software matches the written requirements. A tester needs to know that some requirements might matter more than others, and that half of the real requirements might never have been written down. If a candidate talks about risk-based testing, then she'd better go beyond the buzzwords and demonstrate a real understanding of what it is and how to accomplish it.
Delve into Work and School Experiences
Evaluating analytical skills or problem-solving abilities is not easy. I try to do this by asking testers how they approach problems. I pose a hypothetical problem and ask the candidate to suggest ways to solve it. I also ask for a specific example of a difficult testing problem the candidate has solved and the method she used. Again, there are no right answers. I'm looking for a sense of method, but also for creativity and the flexibility to adapt an approach to different circumstances. I'm especially interested in people who know what a model is, and why it might be a useful tool in analyzing and solving problems. I'm even more interested in candidates who understand that models have limitations.
Candidates must also possess critical intelligence. One indicator of critical intelligence is a candidate's description and assessment of the various sources of project information. I ask interviewees to give examples of the sources they've dealt with and others they know of. What issues did they encounter in getting and evaluating information? Were all sources equally credible? If not, what did they do about that? How might they cross-check different sources? Finally, knowing what a candidate has studied or done in a former life can help guide interview questions that show her qualities of mind.