Thursday, 17 January 2013

When context really matters: entertainment, safety ... or neither?

Yesterday, Mark Handley drew my attention to a video of the recent evacuation of an All Nippon Airways Boeing 787 due to a battery problem: "Here's a video from inside the plane:  The inflight entertainment system has clearly just rebooted, and about half the screens are displaying the message "Please Wait" in large comforting letters. Maybe not the most appropriate message when you want people to evacuate quickly!"

Fortunately, it seems that passengers ignored the message asking them to wait, and did indeed evacuate instead. But did they do so as quickly as they might have done otherwise? We'll never know. They will have had many other sources of information available at the time, of which the most powerful were probably other people's behaviour and the appearance of the evacuation slides. The digital and physical contexts were providing different cues to action.

Brad Karp observed that : "Presumably when you activate the slides, you either want to kill the entertainment system or have it display "EVACUATE!"

Alan Cooper, in "The inmates are running the asylum", discusses many examples of interaction design. One he explores is the challenge of designing good in-flight entertainment systems. For example, he points out that the computer scientist's tendency to deal with only three numbers (0, 1, infinity) is inappropriate when choosing a maximum number of films to make available on a flight, and that choosing a reasonable (finite) number makes possible attractive interaction options that don't scale well to infinity. He also argues that the entertainment system needs two different interfaces: one for the passenger and a different one for the crew who need to manage it. But if you watch the video, you will see that half the screens on the plane are showing a reboot sequence. Who designed this as an interface for passengers? If the system developers don't even think to replace a basic reboot sequence by something more engaging or informative, what chance of them thinking about the bigger picture of how the entertainment system might be situated within, and interact with, the broader avionics system?

In-flight entertainment systems don't seem to be considered as part of the safety system of the aircraft. Surely, they should be. But that requires a broader "systems" perspective when designing, to give passengers more contextually relevant information that situates the digital more appropriately within the physical context.

Happy (entertaining, safe) flying!

Wednesday, 9 January 2013

Sometimes it just works!

Last week, we were in Spain, enjoying the sunshine and using the motorways. And I was really impressed by their toll machines: attractive, easy to use, and even delightful. Even though they were taking our money. My very amateur video of the machine in action isn't great (sorry!), but it shows the key features of the system.


1) The instructions screen presents a clear representation of what to do next, independent of language. This isn't essential, but provides backup for those who might not be able to interpret the main interface.

2) Each action is clearly illuminated in a timely way: insert ticket; pay (card, notes / coins); get change; optionally, get receipt. Sure, the action sequence is simple, and there's limited scope for error, but the device leaves little room for doubt. [Contrast this with the story a colleague told me of observing someone buying a ticket from a UK rail ticket machine who could not locate a notes slot, so folded up a £5 note and fed it carefully into the coin slot.]

3) The coin slot, in particular, is well designed, opening and closing smoothly to accept coins at just the right time.

I know it's simple, but that's surely the point: it's only as complicated as it needs to be, and no more, and it's easy even for someone who speaks no Spanish to use without help.

Human–Computer Interaction specialists like me tend to notice poor features of interactive systems; it's delightful to celebrate a system that really seems to work well, come rain or shine.