Affordances are relative

Affordances, those features of a product that help you figure out how to use it, are relative.

Most of the busses in the Kitchener-Waterloo region have rear doors that open when you wave your hand in front of them. The one I took downtown this morning must have been an older model because it just had two vertical push bars on the doors.

When we arrived at the terminal, the young woman at the front of the queue to get off started to wave her hands in front of the door, which did not respond. Puzzled and alarmed, she began to shout at the driver to open the doors, until someone behind her said, “push the handle”.

“Oh,” she said, chagrined, before she hurried off into the crowd.

Door handles are a common textbook example of affordances. But affordances, it seems, are relative.

We talk a lot about making interfaces intuitive. But intuitive simply means, corresponds to my intuition. And my intuition simply means my guess based on how other stuff I use works.

Intuitive is relative.

Which is why the need for documentation will not disappear entirely from the earth, but also why our standards for what needs to be documented have to change over time.

Documentation fills the gaps left by affordances and intuition. They are relative, and documentation must be too.

2 Responses to Affordances are relative

  1. Tom Guarnera 2016/07/08 at 14:35 #

    This is a great reminder that what seems obvious to us, may not be so obvious to others. Back in the day, I was a low paid draftsman. In my apartment, I had a drafting table, but I did not have a kitchen table, end table, coffee table. Just a multi-purpose drafting table. I was also a college student taking classes in communications. I used the table as an example for one of my papers. If a boss tells a worker to go to the warehouse and bring back a table, there are many choices that could be made. Depending on the relative information (past experience, choices of tables), the employee may not make the right choice. As you said, documentation hopefully bridges the gaps of relative knowledge. Thanks for the blog post.

    • Mark Baker 2016/07/10 at 23:01 #

      Thanks for the comment, Tom.

      Indeed, we tend to use language in very situation-specific ways. This is something I have written about before, particularly here:

      Affordances, of course, are a form of language — a form of physical expression through symbols — and the same thing applies. We interpret the symbols as we interpret words, in the context of our present lives and concerns.

      So often, problems of understanding do not arise from the inherent complexity of a thing, but simply from an unfamiliar circumstance.