Y Combinator’s Kevin Hale: what toilets can teach us about user experience

There’s this joke about a super drunk guy at a bar called Larry. He realizes he has to poop. The bartender tells him where the washroom is, and off he goes.

Larry lets out a scream from behind closed doors. Seconds later, he lets another one out. The bartender rushes into the toilet, bangs on the door, and asks what’s going on. “You’re scaring customers,” he says.

“I don’t know. Every time I flush, something comes up and squeezes my nuts,” says Larry, grimacing. The bartender comes in, and realises Larry is sh****ng into the mop bucket.

Kevin Hale told this story at a keynote session of Tech in Asia Singapore 2015 to illustrate a point. A toilet sink and a mop bucket share a lot of similarities. They’re both containers of water, have equivalent heights and handles, and they’re located in the bathroom.

But even sober folks are susceptible to confusion, as some lawmakers found out when they mistook a mop sink for a Muslim foot washing sink:

The joke illustrates something called false affordance. Affordance is a design concept signifying a potential action enabled by an object. Using a mop bucket as a toilet sink is an example of false affordance. In other words, it’s making wrong assumptions about what we can do with an object.

There are times when false affordances work in our favor. Many office thermostats don’t work because the air-conditioning temperature is set by a central computer. Nonetheless, it gives tenants an illusion of control – a placebo effect that leaves them contented to think actual change has occurred.

In many cases, however, it frustrates users. False affordances should generally be avoided. While many toilets do that by hiding their mop sinks, “hiding valuable features is ridiculous,” says Hale, because users should ideally find them with no trouble.

The key to eliminating false affordances lies in what’s called the intuition and knowledge spectrum:

So there are two ways to close the gap. One, increase the knowledge of users through documentation. Two, make the app intuitive and easy to use. The second way is ideal.

Think about the things that need documentation: programming languages, APIs, and airplane maintenance. These things are usually accessible only after years of training by a select group of people.

App design therefore should gently guide users towards the desired behavior. Witness thefly stickers in male urinals: they’ve been documented to increase cleanliness in toilets by tapping into our instinct to aim.

A negative example would be sink designs, which have evolved from something entirely functional to something aesthetically pleasing but difficult to grasp.

Witness the clear markings: red for hot, blue for cold. To get water, turn the lever anti-clockwise. Easy.

Gradually however, designs evolved into this:

While aesthetically pleasing, it creates confusion. Users take a while to figure out how to get the water flowing and how to activate the cold or hot water. It sacrifices usability for sleekness.

There are times though when convention has to be broken, especially in the name of innovation. How can you go about it yet at the same time give users a pleasant ride? Besides adopting the time-honored practice of skeumorphism, another useful tool is the power of practice. To put it simply, more practice leads to better performance.

Hence user interfaces should nudge people towards repeating an action until it becomes automatic, without the need to refer to manuals. It’s the fly in the urinal – men instinctively know to aim without any instructions.

Here’s an example in software terms:

The “Beta 3″ version of the iOS slide to unlock feature confused many users. It lacked a prompt guiding users on which way to slide their finger. Worse, the “up” arrow at the bottom is situated near the prompt, causing users to mistakenly swipe upwards. The problem was fixed by “Beta 4″ using an arrow sign which hints at the right way to do it.

Such simple measures go a long way towards avoiding false affordances and creating a product that is simple to grasp.

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This article by Terence Lee originally appeared on Tech in Asia, a Burn Media publishing partner. Image: Tech in Asia.