Guest Commentary - The Fallacy of "Logical" Design

This image was lost some time after publication, but you can still view it here.
This image was lost some time after publication, but you can still view it here.

Elegance, logic, simplicity, economy: these are the buzzwords that design geeks live for. If only all the gadgets and devices and feature laden wonder packages made sense then wouldn't the world be a better place? And then we all nod and whine about how we don't know how to use two thirds of the features on our digital cameras.

It sounds great, but there's a problem here: it's that, in fact, lots of gadgets are designed with elegance and logic in mind. It's just that people aren't. People work in funny ways, and some of the ways of doing things that they like most are exactly the ones that don't make sense.
Take the ubiquitous hierarchical menus of the digital camera world. God knows how much effort has been devoted to putting together just the right sequence of menu presses, organized with Dewey decimal clarity and maximum button placement economy.

The thing is, people don't need economy and logic. They need intuitiveness, which is not the same thing. They like dials and knobs. I have, for instance, an old (film) camera called the Pentax ZX-5n. That particular camera, from the mid-90s, is something of a fetish item among interface connoisseurs. I paid a premium for the old used camera a year ago; in fact, I paid more than I would have for a brand new Minolta or Canon. Unlike most autofocus cameras, the ZX-5n was built with controls that almost exactly mirror older manual focus models. There is an aperture dial, a shutter speed dial, and an exposure compensation dial.


Now is this more logical or economical than Canon's cleverly designed menu systems? Hell no! It's just plain more usable. It might sound messy on a spec sheet, but actual human beings easily remember what knob or dial to turn for what. They don't easily remember what menu choice to navigate to. The reason why some of us are automatically drawn to older, low tech objects like the Pentax ZX-5n is not because they are more "logically" designed (well, in some ways they are, but we'll leave that aside for now) but because they take advantage of easy, tactile design cues that are actually much easier for real human beings to manage than abstract logical hierarchies.

There is not a single low end digital camera model right now that has an exposure compensation dial. This is pretty amazing because, first, proper exposure is a lot more important with digital than with computer film, second, the ability to easily analyze and adjust exposure is one of the big advantages of digital, and finally, the basic notion of making pictures lighter or darker is pretty darn easy for people to understand. Even my mid-60s vintage Polaroid has a lighten-darken wheel. So, then, why not put in this kind of a dial? (Bonus points: it can automatically call up a histogram, too!) The answer, from the point of view of a designer at an electronics company, is that it messes up the beautifully organized logic of his camera's menu system. It just doesn't make sense, from the standpoints of logic, economy, elegance and simplicity, to have a bunch of separate dials for commonly used features—especially if they'll actually duplicate commands already available in the menu system. Isn't one basic, easy to explain system for choosing commands and features obviously better?

In a word, no. Easy to explain isn't the same as easy to use. Logic is nice, but intuition is better. You wonder why people don't use the features on their digital cameras? Try giving them some knobs to turn and switches to flick. -Mark Gimein

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