User Centered Design (UCD) seems to be growing in popularity, and it’s not strange. Who could be against the user being the center of the design process? But looking beyond this popularity it turns out that there is not a consensus about what UCD is.
Formal definitions like in Wikipedia or ISO 13407:1999 describe it vaguely using terms as “design philosophies”, “models”, “general guidelines”, “recommendations”, … All those are positive instructions, but they aren’t really useful when you face a real project developing a real interface.
What do we actually have?
Actually UCD refers almost always to a set of techniques that may be applied along all the life-cycle of a software application; the only thing those techniques have in common is that users are their main roles (at least theoretically). The number of techniques included may vary from six (like in this Webcredible article) to several tens (like in this interactive table at UsabilityNet). Those techniques may be as different between them as focus groups, user testing and interface prototyping.
Oddly some UCD techniques don’t include real users in their carrying out: for example, heuristic evaluations of usability.