Tuesday, June 23, 2009

Principle of Least Astonishment - Fail

I've been thinking a lot about design lately. Mostly because I'm entering the design phase of my thesis and I've reviewing the better chapters of Richardson & Ruby's "RESTful Web Services" and other material. But beyond web services, I've been thinking about "good design" and "bad design" as general principles. I really appreciate it when I encounter a system or service (in the real world or online) and I can come away with a sense that I have just experienced the benefits of good design. Just as strongly, encountering poorly designed systems really leave a sour taste in my mouth.

I won't do business with a company that has what I consider to be a poorly designed or poorly implemented web presence. Just my choice. I'd prefer to support good design by directing my business to organizations that, at the very least, share my aesthetic for design principles. I realize this is often a subjective evaluation and I'm not apologizing for it. But I think certain aspects of design can be widely recognized as very poor, outside of any aestheticical tastes.

The example I have in mind is the system at my local library. Now don't get me wrong, I love my local library and have a tremendous respect for libraries in general. But across my city, the library has rolled out a self service checkout system which badly violates the principle of least astonishment. I'm a pretty tech savvy person. I love to figure out new systems. But I end up misstepping every time I try to check out library materials. And I'm not the only one. As far as I have seen, everyone stumbles with this system because it combines familiar interfaces with unfamiliar uses.

The system works like this, there is a bar code reader, a touch screen interface, and a glass plate. The expected use case appears to be scan the card in the bar code reader, then touch the screen to confirm that the card read was correct, place items on the glass plate where they are identified "magically" (magnetic strip?), confirm the items are correct, once all the items are scanned confirm that you are done, your "receipt" prints out and you leave. Sounds good, right?

Well, it doesn't quite work out. This system is actually replacing another self serve system that was entirely bar code driven. I don't know why they ditched the other system. It worked fine, as far as I could see, and all library materials, including new materials already have a library issued bar code sticker. People are familiar with bar code readers, everyone in the western world has had a lifetime of barcode training by watching items be scanned in at the checkout, and by now most people have experienced self serve checkouts where you scan your own. So what's the first thing that everyone does when checking out books? They hold them up to the bar code reader! When that doesn't work, they try to swipe the barcode over the glass plate and place it aside, which results in the item appearing then disappearing from the confirmation touchscreen.

So what happens? People are generally capable of figuring this out and they learn, right? Nope. Doesn't seem to happen for two reasons: 1) Inevitably the helpful librarians who have been hovering inches away now swoop in and do it for you, oblivious to all protests and completely negating the value of self service checkout; and, 2) Weak technology. The scan plate is touchy, too many items on it and it gets confused - four items is okay, five sometimes, but a sixth item inevitably causes it to decide that only three are on the plate and all must be removed and the process restarted. The bar code reader requires that the library card be place on the desk for it to work, the natural behaviour of holding it up the reader fails. And the touch screen is unclear about where to press and when and how many times (in fact, it requires an unprompted, second press of "No" at the end of the process for it to ever conclude the session).

At the end of the day, it's not a big deal. No one dies. Everyone gets their items. People will eventually adjust and the technology can be upgraded to remediate some of the touchiness at the cost of only a few hundred thousand dollars more spending in a city with multi-billion dollar deficits. But it irks me. And I think it illustrates something that all designers should take as a lesson, understand the expecations of your users and work with them. It will be to your benefit and theirs.

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