Design comes in a number of dominant (but not exclusive) flavours:
- Engineering-centric: optimising for the artefact, including choice of materials, serviceability, ease of development and interoperability;
- Marketing-centric: optimising for saleability by adding features, speed to market, and brand coherence;
- Business-centric: optimising for such things as cost per unit, strategic alignment, and distribution channels; and
- User-centric: optimising design for the understanding, behaviours, and physical capabilities of the intended users.
Unfortunately, engineering-centric, marketing-centric and business-centric design can just come across as thoughtless design.
I’m typing this from a hotel in Sydney. In the shower is the tap fitting you see above: an example of thoughtless design.
Take a moment to reflect on how you think it may work.
Certain artefacts have culturally informed conventions: sometimes known as affordances. This is how we expect things will work. For example, here in Australia we expect that:
- Left or down are negative: backward, past, or decreasing;
- Right or up are positive: forward, future, or increasing.
And given a specific context (in this case, a tap fitting), we have conventions like:
- Turning a tap anti-clockwise opens the valve;
- Turning a tap clockwise closes the valve.
However, in the case of the pictured tap fitting, the expectations the user has are contradicted:
- Turning the tap anti-clockwise increases the indicated water temperature; and
- Moving the slider to the right increases the flow of water.
If someone enters the shower half-asleep, turns the tap anti-clockwise and no water comes out, they may try moving the slider and end up scalding themself.
Since both types of control are available, there’s no excuse that the designer didn’t align the functions with the users’ expectations, so that:
- Turning the tap anti-clockwise increases the flow of water; and
- Moving the slider to the right increases the water temperature.
The worst part is, a user that gets scalded would probably blame it on their own incompetence – instead of complaining to the hotel about the thoughtless design.
I’ve since been told by @Aus_Pol that this type of tap fitting is common in certain parts of North America. Specifically, he’s seen it in “4 different places of Canada (and Seattle).” Personally, I’ve only seen it in a couple of places in the States, including Maryland and I think, Texas.
After having to use the shower again, I noticed something else. The potential issue of someone burning themself due to the thoughtless design contravening user expectations has obviously been encountered by the designers.
The red button shown has to be pressed whilst turning the tap to set the temperature above 38 degrees Celsius (body temperature). I originally didn’t notice this because the temperature was already set to over 50degrees (nobody would have a shower at 38degrees C – brrr!).
Even when I turned the tap full circle either way, I depressed the button without knowing it. I have large-ish hands, so by grabbing the tap handle and turning it, I accidentally held the button in.
In both cases, I could unknowingly increase the temperature to 70deg C (enough to scald) – negating the new design feature.
This is a great example of the type of design that results from a corporate culture. It may have evolved (as most product designs do) along these lines:
Business requirement: The tap fitting has to be a single unit, using current parts to keep costs down.
And hurry it up, we have orders to fill.
Engineering-centric design: First, design the water-flow control. Put it at the back of the fitting, so it’s out of the way. A rotating lever will do the trick.
Next, design the temperature control. We’ll just use one of our normal taps for that to keep costs down. Problem solved.
People are burning themselves.
Engineering response: “Stupid users. Didn’t they read the manual?”
Business response: “Well, we can’t go back to the drawing board. It would cost too much to re-design and re-tool. Make a modification to fix this.”
Business requirement: Stop people burning themselves.
Engineering-centric design: Add numbers to the temperature controller, so the users know they are turning the temperature up, not down.
People are STILL burning themselves.
Engineering response: “Stupid users. Didn’t they see the numbers?”
Business response: “Even if it’s user error, we have to at least reach a break-even level of lawsuits.”
Business requirement: Stop people burning themselves.
Engineering-centric design: Add a button that has to be depressed before the user can move the water temperature beyond body temperature.
People are STILL burning themselves, but our lawyers have said we’re OK because we’ve added enough features to try and counter their stupidity.
Business response: “We’re covered. Leave good enough alone and move on to the next product.”
This of course resulted in a complex, expensive design that still contradicts user expectations and is still a danger.
Instead of investigating users’ mental models of how taps work, they started with a thoughtless concept and continued evolving design from bad to worse. This shortcut mentality meant that the project went:
- Over budget on development (multiple release iterations);
- Over time on development (multiple release iterations);
- The end product cost more to manufacture (due to complexity); and
- Resulted in an unintuitive tap fitting that is dangerous to use.
If the organisation had of done some foundational research to understand people’s mental models of how taps work, and designed for it, they would have saved on development time and product complexity, lowering the cost for development and production of each unit.
Unfortunately, this is the type of development process that corporations encourage (the industrial, production line model: the underlying philosophy of corporations) – and the reason why there are so many bad designs out there.
Can you imagine how much cheaper it would have been to do a bit of user research up front?
Thanks to @mattmorphett for pointing out a mistake (which I’ve since corrected) in the operation. He’s also got a great post on taps and conventions: Sometimes there’s a good reason to break convention