We all think about user interface more often than we realize. From our cell phone, to our DVR, to Facebook, or the parking garage kiosk we fight with leaving work each day, UI is everywhere – and has truly become a functional art form. And as we continue to add more devices and electronic gadgets into our circle of daily interactions the quality of that experience continues to grow ever more important.

Dave Hogue, October 2011 (Michael Clawson / Flickr)

User interface/experience is a topic that comes up again and again at tech conferences like SXSW Interactive. Last year, UK designers Cennydd Bowles and James Box gave an excellent presentation on how interaction design is like music. This year saw another outstanding presentation on the subject, this time from Dave Hogue, who heads up Experience Design at San Francisco interactive agency Fluid – but who came to the position from a successful (and still ongoing) academic career, with a doctorate and stint as professor of psychology at Xavier University in New Orleans.

Hogue built his talk around a specific premise: Complexity is easy, but simple is hard. As Bowles/Box mentioned last year, government forms are a great example – they get designed, augmented and stuffed to the gills with questions and explanations coming from multiple departments without anyone taking the time to make them easier to navigate. And it happens everywhere – whether it’s a website, a form or a brochure, too many stakeholders weigh in until the product is irreversibly cluttered.

You may be familiar with the butterfly effect – the idea, interwoven with chaos theory, that a small systematic change now can have huge effects down the road. Hogue says this concept is an integral part of user-experience design, because bad decisions are made (or good decisions aren’t made) early on in the design process that can have a catastrophic impact on the final result.

This brings us to the complexity curve. When you start a design project, you’re energized, infused with a can-do spirit that makes even dense and complex projects seem easy. But the complexity grows as you dive in and more of the “by the way…”, “wouldn’t it be cool if…” and “looks good, but let’s add x” comments get thrown into the mix by well-meaning contributors. The scope increases, or you try to copy ideas you’ve seen work elsewhere, or you make other mistakes that will likely be extremely hard to clean up later. And once you get to the top of the complexity curve, you hit a wall when you find out that the confines of the project (or the materials or technical limitations) can’t support all the features you’ve tried to squeeze in. Getting through the last, downward part of the curve to a successful, usable design ends up being the hardest part.

Hogue cautions, however, not to confuse complexity with difficulty. The best-designed products – the iPhone, for example – often remain quite complex, but you can figure them out because they’re just so intuitive. You also have to be eternally patient, as the most intuitive design often comes after years of research and development. He cited the example of the first digital watch, the Pulsar (left), which took months of work by the Hamilton Clock Company to develop after they built an initial digital prototype at the request of Stanley Kubrick for 2001: A Space Odyssey. And the iPhone included many advancements developed incrementally by Apple designers for its predecessor, the iPod.

Designers, here’s Hogue’s list of ways you could end up not focusing on simplicity – and going down the wrong path:

1. By not listening to initial feedback. If people say it’s messy and confusing, it is – and your product could end up being irrelevant or ambiguous.

2. By disconnecting action (how it works) from outcome (what users are trying to accomplish) – thus making your product harder to use.

3. By trying to design your product to be everything to everyone: Too many variables, too little focus and design by committee.

4. By allowing in too many “nice to have” options can introduce noise, clutter and excess.

5. By copying solutions: They could work in other situations, but be misapplied to yours.

6. By designing to your limitations, by which you expose the system model (how the sausage is made) rather than designing for what you want it to do.

7. By focusing on including the latest technological bells and whistles, you may be trying to solve a wrong or non-existent problem. However, it could also be a tremendous opportunity – so you have to be able to figure that out for yourself.

8. By designing for yourself, without listening to ANYONE else at all. Again, sound judgement can be your friend.

9. By accepting assumptions: Don’t design based on how you THINK people will use your product.

10. And on a related note, by not collecting data before you start. Research and critical thinking are your friends.

We’re all motivated users who want to learn. We’ll tolerate difficulty and confusion in trying to use something – but only to a certain extent. So when you start a design, ask important questions: What are users trying to accomplish? How will they use it? How will it make them feel?

Hogue’s conclusion is that by involving creativity and critical thinking to design a clear path for users to accomplish a task – and being equally clear in your accompanying instructions – you’re much more likely to make something people will like and want to use.