In working on web design and DVD authoring, we're constantly focusing on making the user interface easy to understand and use. Every job is different, with different goals to meet and limitations to accommodate. When it comes to complexity of functionality, these two media represent opposite ends of the poles: Drupal-powered websites have much complexity, while DVDs are incredibly simple. Yet optimizing usability of these two vastly different interactive formats can be very challenging. This is because complexity in itself is not a barrier to ease of use. Complexity is not a disease.

Recently on his blog, Drupal founder Dries Buytaert wrote:

The Ockham's Razor Principle of Content Management Systems says that given two functionally equivalent content management systems, the simplest one will be chosen. It asserts that simplicity is preferred to complexity. As content management systems become more alike in terms of critical functionality, ease of use will become a key differentiator (rather then functionality).

In addition, web application frameworks like Ruby on Rails, whose goal is to develop applications with as little code as possible, are redefining the rules of how websites are built. For web application developers, ease of development will become a key differentiator.

Complexity is a disease.

Much as I hate to disagree with Dries, I truly do not believe that simplicity itself makes for "ease of use." Usability arises from many different principles, of which simplicity in the abstract hardly ranks.

Case in point: DVDs vs. Drupal-powered websites. DVDs can be aggravatingly unusable, despite their inherent architectural simplicity. On the other hand, websites powered by anything can be incredibly easy to use and understand, even without disabling rich and complex functionality.

To Dries' post, I responded, in part:

I'm not so sure that simpler is always better. Which is easier to drive: A BMW? or a prototype car that just has a joystick? The BMW, with steering wheel, pedals and gear shift, is much more complex in terms of user interface, but for most people it is also easier to use, despite the fact that the prototype vehicle with just a singular joystick is obviously a much simpler interface. Existing patterns of use always come into play.

In another example: A looping handle on a door you can only push open is bad design, no matter how simple it is. People will take a cue from the design and try to pull that door open. A push-latch bar on a door, on the other hand, is much more complex to design and manufacture, but it is infinitely easier for people to use. Very few people will try to pull open that door.

Complexity isn't a disease -- confusion is the disease. Complexity often leads to confusion, and that's a problem. But complexity in itself doesn't have to confuse. All you have to do is listen to a Beethoven symphony to hear the proof of that.

When it comes to making a website easy to use, we're always balancing principles such as affordance, accessibility, chunking, signal-to-noise ratio, forgiveness, feedback, the list goes on. The law of parsimony, which people call Ockham's Razor, is but one part of the picture -- and taken to its extreme, can lead to maddeningly unusable design.

One of the greatest appeals for me about Drupal is its inherent flexibility and capacity for very complex content management. The challenge for me, as a designer, is to make that complexity into something usable. Sometimes that means simplifying choices or function, but mostly I'm focusing on clarity and affordance. As new, more powerful functions and features are being added every day to the Drupal core and contribution repository, sometimes ease of use can slip away from us for a while. It's gratifying to read of Dries' interest in adding to the Drupal development process a real focus on ease of use -- especially since I do not believe Drupal has to lose any of its robust complexity in order to achieve this.

One of the very exciting developments to arise in last week's worldwide Drupal developers' conference call was discussion on revamping the entire theming architecture of Drupal, so that, eventually, all of the content presentation is called and handled by the theme. So far, much of our work in designing Drupal themes is in handling information that is pushed out from the CMS. Changing this paradigm into a pull mechanism can make for some exciting new ways we can develop user interfaces for Drupal-powered sites in the future.

Related and recommended: "Universal Principles of Design", by William Lidwell, Kritina Holden and Jill Butler (Rockport Publishers: 2003).

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