Would you trust a plumber to design and decorate the interior of your new home? How about an auto mechanic to paint your car? Or a dermatologist to perform your root canal? If you answered no to any of these questions, then I would argue just as strongly that functional testers should not be handling usability testing for your software.
To be absolutely clear, there are some talented functional testers who are gifted in usability testing as well. However, this is typically the exception. The point of this blog post is not to minimize these exceptions, but rather to highlight the differences between these two testing types and point to the necessity of having one set of experts test your software for functionality, and another set of experts test for usability.
So why do we need separate experts? Here are several noteworthy observations:
- Different fields of study: In general, usability testing experts come from non-technical fields of study – psychology, cognitive science, human behavior, marketing, etc.
- Different skills required: In general, functional testers have more in common with engineers and scientists while usability testers have more in common with artists and psychologists
- Different focus: In general, functional testers focus on “how can I break this” whereas usability testers focus on “how intuitive is this for the end customer”
- Different persona: In general, functional testers do not need to fully understand how an end user would use the software whereas the usability tester needs to study and emulate end users
- Different departments in the workplace: In general, usability testing lives in the product management and marketing department while functional testing lives in the engineering department
Given these differences, in particular regarding fields of study and skill sets, I would recommend against entrusting your usability testing to the typical functional tester (the opposite is true as well – entrusting your functional testing to the typical usability tester could be disastrous). There is a particular art and science to usability testing that requires an entirely different approach and mindset. So from a company’s perspective, it’s best to separate these roles and recognize their distinct value propositions.