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Want to spot a bad interface? Look for this tell–tale sign.

Want to spot a bad interface? Look for this tell–tale sign.

A lifetime in design warns even the most zealous of design professionals to be wary of dogmas claiming to be universal.  It is the experience of this author that no sooner has a principle been deemed to be absolute that a use case emerges that requires breaking the rule which it turns out wasn’t so unconditional after all.

Among the small list of design characteristics which we can boldly claim to be universally applicable are perceivable and predictable.  This means that a user should readily understand what an interface offers, and that the interface should behave how the user anticipates.  Or to put it in layman’s language, how a user thinks the interface should work, and how it actually works are the same.  A user should be able to guess how the interface works based on a cursory view of it, and be correct.

It is tempting, yet incorrect, to draw the conclusion from this principle that a design should never offer instruction to users.  Of course, it is better that an interface works intuitively than that it works with instruction, but it’s just too simplistic and lacking in nuance to claim that instructions are bad in all contexts. The control panel in the cockpit of a Boeing 747 is a magnificent piece of design, and is no less so because the pilots who use it have to go through years of training and instruction before being allowed to do so.

The same is true of a sound mixing desk or an industrial control panel, and in the digital sphere it is true of systems to register for VAT or apply online in real time for a mortgage.  In those digital examples, users benefit from, and appreciate detail around what specific information is needed, and where it can be found.  Gentle instruction and guidance are critical in giving the user positive feelings of confidence and control.

Could I propose therefore that the principle shouldn’t be the black and white “never instruct the user” but rather the shades of grey “don’t over–instruct the user?”  This may sound ambiguous however you might be surprised how easy it is to spot when you are alert to it.  In fact, when you are aware of it you will see evidence of its existence in the real world and on digital platforms with alarming regularity.

COVID–19 notwithstanding, for twenty years I have been a very regular traveller on the Belfast Dublin train.  I have been on the train at least once a week, every week, for three jobs and two decades.  I am familiar with every part of the 120 miles of track that connects the two cities, and am very appreciative of the strong coffee, hearty breakfast and friendly hospitality of the team on board there.  On the two–hour journey one occasionally needs to visit the bathroom, which in itself is an event unworthy of comment, except for the fact that such a visit requires the washing of hands afterwards, which in turn requires working out how the interface below operates.


Sink on Enterprise train

Fathom (image owner). Enterprise sink. [digital image]. Retrieved from author.

The interface comprises three labels and a button.  The three labels are for soap, water and dryer (in English and Irish, and with braille) along with a button just below the dryer.  So how does it work?  And does it work the way the user expects it to work?  Well I have put these questions to nearly 1,000 people in 10 countries and the most common answers are:

Get soap on hands? Place hands below Soap label.

Get water on hands? Place hands below Water label.

Dry hands? Usually 50/50 between place hands below Dryer label and press button below Dryer label.

The bad news is that these answers are wrong, and worse still in my five years of asking this question no one has ever got this right.  I stress this isn’t because I happen to be hanging around technophobes who are terrified of buttons and automation, but rather because the interface is so appallingly designed.  Here are the right answers:

Get soap on hands? Place hands below Soap label.

Get water on hands? Press button below Dryer label.

Dry hands? Place hands below Dryer label.

Now this right answer is just so awful that over the years when I have shared it I’ve sensed that people scarcely believe me, convinced that I was just asking the question to make a point and then made up a terrible answer to try to somehow explain the importance of perceivable and predictable.

A number of months ago, the Enterprise (the name of the train service) updated their interface.  What’s more, they updated it in a way which confirmed that I wasn’t making it up.  Can you spot the difference?


Sink on Enterprise train, with label

Fathom (image owner). Enterprise sink label. [digital image]. Retrieved from author.

This a very obvious example of a poor interface trying to cover over its crimes with over–instruction.  The label is overly–large and overly–dominant.  For nearly fifty years now I have washed my hands 3 or 4 times a day without instruction and the fact that I required instruction here merely illustrates the paucity of the interface.

Our friends on the Enterprise aren’t alone in making public conveniences more confusing than they need to be.  The otherwise outstanding Dynamic Earth in Edinburgh boasts no fewer than five signs for the dryers in their gents.


Gent's dryers at Dynamic Earth

Fathom (image owner). Dynamic earth dryers. [digital image]. Retrieved from author.

Moving to a subject closer to the author’s own heart (and heart rate) let’s consider the interface on coffee machines.  As coffee becomes an increasingly prominent part of modern life, we encounter coffee machines more regularly in public environments; from shops to petrol stations, from museums to sports stadia.  And here is how we would like them to work:


A well-designed coffee machine

Fathom (image owner). Studio coffee machine. [digital image]. Retrieved from author.

Press the big button for a cappuccino.  Press the other big button for an espresso.  And so on.

There’s no way a designer could design such a simple machine so badly that instruction would be required, is there?


Coffee machine with garish instruction taped on

Fathom (image owner). Nescafe Coffee Machine. [digital image]. Retrieved from author.


If that signage doesn’t give you a caffeine headache, nothing will. I hope the machine has been upgraded to include an Irish coffee option, to take the edge off the user’s nerves!

There are times however, when interface quality can be a matter of life and death, or at least a matter of personal safety.  One such example is crossing the road.  See below some interfaces we are commonly presented with when we want to cross the road.  One of many flaws on the interface on the right is that the green man, giving you permission to cross the road, is on the control panel, not on the other side of the road.  So, if it’s a busy junction and you aren’t able to see the control panel, you don’t know the colour of the man.  What’s worse, if the box is at a crossroads, it is practically impossible to know which direction the man is giving you permission to cross in.  (There’s a small clue on the interface, but I’ll let you find that for yourself.)


Various road-crossing interfaces

Fathom (image owner). Road crossing. [digital image]. Retrieved from author.

Where interfaces of this low quality appear, over–instructing inevitably follows.  See below a control panel and sign from East Belfast.

Interface to cross the road with an instruction notice

Fathom (image owner). Road crossing East Belfast. [digital image]. Retrieved from author.

Just pause for a moment to take this in.  There are instructions on the post to help people use an interface that used to be usable by 4– or 5–year–old kids. This is an admission of an unacceptably low–quality interface.

To be slightly more serious, ask how the powers that be knew to put the sign up?  It can only have been because there have been accidents near the crossing and so the sign had to be installed, as a chronic confession that the interface simply wasn’t good enough.

It seems the pattern is clear.  Simple instruction and helpful guidance are evidence of a thoughtful interface.  Over–instruction and patronising–reinforcements are more likely evidence of a thoughtless one.

By Gareth Dunlop

Gareth formed Fathom in 2011 and has been in the business of design performance for over two decades.

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