Consistent interaction conventions

Chip and PIN deviceI stumbled across this Chip and PIN device at a petrol station near Swindon last. I was reminded me of a talk by Jeremy Rewse-Davies (Design director of London Transport) some time ago where tube station employees had adapted poorly concieved posters to meet the needs of the public.

Without previously acknowledging it, most Chip and PIN devices across the world have a 'enter', 'OK' or green button on the bottom right-hand corner of the keyboard. This is usually the key you press once you have tapped in your PIN. Often the 'OK' button is larger than the other keys to increase visual impact.

However, in this example - the green key is not in the bottom right-hand corner. It is the same size as the other keys and it is obscurely situated one key from the right; it also incorporates an unconventional 'E' printed on the key.

This entirely breaks the design conventions used on not only on other Chip and PIN devices, but also calculators and other interactive dialogues which instigate a user response.

In this case, the poor petrol station attendant has obviously got a little fed up of folk not being able to use the device and has stuck on a big arrow instructing customers to 'please press'.

When I went to use the device, I immediately ignored the stuck-on note (as hand written notes often incur less authority) and went straight for the 'Fn' key after inputting my PIN code.

I had a little smile when I realised what was going on, but soon got a little stressed when I realised that there were 5 folk behind me in the queue waiting to use the machine.

I wonder what the impact of this design error has been?:

  • Think about how many folk use this device every day.
  • Think about how many times the petrol station attendant has to explain the note
  • Think about how many folk with poor or impaired eyesight get confused by the legibility of the handwritten note
  • Think about how much time is lost as folk incorrectly press the 'Fn' button instead of the green 'E'
  • Think about how much time it takes to decipher the handwritten note and the purpose of the 'E' key.

Point-of-sale technology often assists in improving of customer turnaround... and yet this device seems to disrupt that process immeasurably.