User-centered design means understanding what your users need, how they think, and how they behave - and incorporating that understanding into every aspect of your process.

At Adaptive Path, we've been doing our own work with Ajax over the last several months, and we're realizing we've only scratched the surface of the rich interaction and responsiveness that Ajax applications can provide.

I'm not sure that you can say definitively that some roles are better filled by consultants, but I would say that some projects are better handled by consultants.

If you need to take a step back from day-to-day operations and plot out the long-term direction of your user experience strategy, consultants can give you a perspective you can't get on your own.

User-centered design means understanding what your users need, how they think, and how they behave - and incorporating that understanding into every aspect of your process.

As much as we may want to withdraw into a world of pure problem solving, we have to acknowledge that the most successful architectures are the ones you can actually convince someone to implement.

But the best teams I've encountered have one important thing in common: their team structure and processes cover a full range of distinct competencies necessary for success.