On Looking: Eleven Walks With Expert Eyes is a book by Alexandra Horowitz on observation. Seeing, hearing, feeling, smelling, all that good stuff. More than that though, On Looking is a book about perspective.

The book is broken into chapters where each chapter is a narrative from the author describing a walk she took around a New York neighborhood with some expert accompanying. The experts range from her toddler, to a geologist, to a person studying pedestrian traffic, to a person studying urban wildlife.

Each chapter stands well on its own. The stories were entertaining and the characters Alexandra walked with were endearing.

Certain characteristics of each expert jump out. Alexandra’s child likes to treat inanimate objects as if they are alive. Cars that aren’t driving around are sleeping, and when leaving steps you have to big them a farewell. The guy studying urban wildlife tended to notice not just the critters but also traces of their existence when they were not around. The man studying pedestrian traffic noticed things about how people walk (hints of illness) that would be invisible to most.

This is such a nice parallel to testing. Testing is sometimes thought of as a team sport. That can be interpreted as meaning that testing isn’t exclusively the job of people that self-identify as a tester. Developers, product folks, support team, and everyone else involved in creating the product, can test.

I had always taken that for granted and didn’t think about the reason it makes sense for multiple types of people to test. At a glance, it seems like the expertise is the important thing. Product people might have a tendency to test the product from a customers perspective, and developers might have a tendency to test in a technical or programmatic way. When I refer to expertise, I mean that in the Collins and Evans sense. But after thinking on this a while, I think there is more to it.

All the biases developed while developing an expertise shade how a person observes the world. This happens to the extent that you do things in an automatic way (system 1). A person studying typography doesn’t force themselves to notice the typeface on signs, it just happens because of years spent intently looking at typefaces. This has biased them to notice text very quickly and in a very specific way.

Tester friends have often commented on their inability to turn off the critical thinking that they have developed to make them a good tester. Developing this skill has changed how they experience the world and get along day to day.

When executing scenario tests, a tester has to role play. They put themselves in a mindset to think about testing in terms of how a user might behave in the software and the benefit they might get from its use. A product manager is biased to think like this because of their daily focus on people using software and the time spent developing their product management skills.

Back to the review. Overall, I enjoyed the book. I think this is a great text for deeper thought on expertise, bias, and how people experience the world in different ways. And, I think there are a lot of ideas that can be directly applied to testing.