An almost clever water dispenser

Here’s your standard water dispenser – you’ve probably seen many of them and most look similar.

A standard water dispenser

A standard water dispenser

You’ve got cold and hot taps which you operate with the red and blue handles.

And now here’s the dispenser which I now face daily:

The "clever" water dispenser

The “clever” water dispenser

At first glance the only difference is that instead of handles you now have to press buttons – blue for cold and red for hot.

Here’s what I’m guessing the designers thought:

  1. Hey, let’s not use those old fashioned handles and instead put cool buttons – it’ll look much nicer.
  2. Yeeeaahhh! We’re awesome!
  3. Oh wait, there’s a small problem – it’s now really easy to unintentionally press the wrong one.
  4. Well hot is used much less than cold… let’s put 2 red buttons so it’s harder to make a mistake.
  5. But let’s make them really small, so it looks better.
  6. We’re awesome again!

Well in the end… the buttons are so small that are actually hard to press and by the time my tea cup is full my fingers are already hurting. So the clever workaround was only meant to hide a general usability problem – the use of buttons instead of something that’s better anyway.

My point – “new” does not always equal “better”. You don’t have to reinvent the wheel. While redesigning keep in mind that it’s supposed to be used by humans.


A horrible water heater

Here’s what I came across – a tankless water heater. I guess those are getting more and more popular recently (just hope this particular model isn’t).

Unusable tankless water heater

The horrible water heater

What do we see here?

  • on/off button (that’s clear)
  • knob with some red and blue markings on the bottom

What do I need to know when washing my hands?

  • how to regulate the water temperature
  • how to regulate the water flow

So how am I supposed to do both with that single knob? Here’s my mental model: turning the knob left/right would control the temperature and the more you turn the more water comes out… but wait – if I turn more to the left would that mean that it also gets hotter? Well I played around with it for quite some time and it turns out that the knob only controls the amount of water and the temperature always remains warm (never hot, never cold). I asked the person next to me (this water heater’s power user :D) how to set it to cold (I simply wanted to drink) and he replied that the only way to do this is to TURN IT OFF.

Well what’s the point of such a thing anyway. You can never drink from the tap and the temperature remains in a position preset by the manufacturer. What if it’s too cold/hot for me?

Walk buttons at pedestrian crossings in Germany

The wide variety of walk buttons inspired this post. I’ll cover the three types I’ve personally come across, but surely there are more.

Let’s start with the worst example. This one here is apparently touch sensitive, but touching the red dot results in absolutely nothing. There is no feedback and no way for you to know if you actually did something (it may as well be a placebo button). It’s so bad that they actually put a large label to explain the usage. And they even messed up the label! It’s written in both German and English, but there’s no separation between the two (and clearly “Touch” is not the direct English translation of “Fußgänger roten Knopf bitte berühren”).

The "no-feedback" walk button

The “no-feedback” walk button.

Now this next one’s a bit better. It’s also touch sensitive, but at least once it registers your action it displays a red sign which tells you everything’s fine. It’s certainly better than the previous example. So what’s the problem here? Well I just don’t like this “let’s use touch sensors to seem more technologically advanced” attitude. I’ve seen people (young and old) trying to press it in all kinds of ways – from touching it gently with one finger, through pressing it 3-4 times just to be sure, to slapping it as hard as possible with the whole palm. And of course the only way to be sure you did it right is to look directly at the device and wait for the red sign.

The advanced touch sensitive walk button.

The advanced touch sensitive walk button.

And here’s my favourite – simple, robust and reliable. It has a real button in the form of a large plate that clearly affords pressing. There’s strong haptic feedback and you’ll be sure of your actions. If not – there’s a red lamp on top (just in case). Too bad someone labeled this as outdated technology, because in my opinion it’s still the best.

Old school walk button (Photo Credit:

Old school walk button (Photo Credit:

Ticket vending machines

The other day I had to buy a ticket from a vending machine similar to this one here:

German Ticket Vending Machine (Photo Credit:

German Ticket Vending Machine (Photo Credit:

The ticket costed 2.50 € and I didn’t want to put in a 50 € bill so I used my bank card.  I entered my PIN, took the ticket and boarded the train calmly. Some time later I got a feeling I might have forgotten something and checked my wallet – I’d left the card in the ticket machine :D. Well the card was recovered (by a friend who was fortunately near) and so the story ends.

Now let’s see why slips like these occur. They are called Premature Conclusion Errors – forgetting to complete the action sequence because the main part of the goal is accomplished (getting my ticket). They are common for activities which people do over and over again.

To those who think “well it’s your fault, because you weren’t paying attention” I’ll say – “of course it isn’t”. The vending machine is clearly poorly designed – it deals with money and allows you to make such an error. What’s the solution? Every single ATM does the following: forces you to pull out the card and only then gives you the cash, thus avoiding precisely this kind of slips. Couldn’t the ticket machine ask me to get the card before spitting out the ticket?

P.S.: I didn’t use the 50 € bill because of fear: what if it gave me 47.50 € in coins. This points out another problem – I don’t understand how it works, so I’m scared to use it.

The usability of window blinds

The other day I was watching Family Guy’s latest episode (“12 and a Half Angry Men”). This funny scene inspired the post.

Peter struggling with the window blinds

Peter struggling with the window blinds

Well I guess the animation says it all. To open/close the blinds you’re supposed to alternately pull on the two strings. Although I knew the theory I could never do it in practice – one of the sides was always lower than the other (that’s not an april fools joke – I really can’t operate those things). Clearly no one wants to have the left part all the way up and the right – halfway down, so why was it designed this way?

Why couldn’t there just be a single string doing all the work or one for opening and one for closing?

Taps in the UK

I was visiting a friend in the UK a while ago and had to face a monster like the one here:

English: Separate taps for hot and cold water ...

Separate taps for hot and cold water in the United Kingdom (Photo credit: Wikipedia)

Now for those of you who haven’t seen this before:

Left tap = hellfire

Right tap = Antarctica

You get two options for washing your hands – move them with lightning speed between the running taps or fill the sink. I guess filling the sink with mixed water is considered the “proper” way. Well I have just one word for you: “hygiene”. That thing actually turns a simple task into an impossible one!

Apparently separate taps are quite common in the UK. It used to be considered quite smart 1 million years ago when diseases were spreading through the hot water and having a mixed tap meant that drinking from it would expose you to the danger (‘cause there would still be some hot water left in the pipe). Good. But it’s time to move on and embrace the modern world 🙂