User Centered Design & Usability

UPA Definition (much more formal and less sarcastic)

There is an international standard that is the basis for many UCD methodologies. This standard (ISO 13407: Human-centred design process) defines a general process for including human-centered activities throughout a development life-cycle, but does not specify exact methods.

In this model, once the need to use a human centered design process has been identified, four activities form the main cycle of work:

  • Specify the context of use Identify the people who will use the product, what they will use it for, and under what conditions they will use it.
  • Specify requirements Identify any business requirements or user goals that must be met for the product to be successful.
  • Create design solutions This part of the process may be done in stages, building from a rough concept to a complete design.
  • Evaluate designs The most important part of this process is that evaluation - ideally through usability testing with actual users - is as integral as quality testing is to good software development.

The process ends - and the product can be released - once the requirements are met.

Most user-centered design methodologies are more detailed in suggesting specific activities, and the time within a process when they should be completed. UCD activities are broken down into four phases: Analysis, Design, Implementation and Deployment, with suggested activities for each phase.


Example design for a complex purchasing process in Brazil known as Consortio (a shared payment method with multiple owners).

My Definition (much less formal and more sarcastic)

User Centered Design can be applied to anything a human can interact with. From the beginning of humans existance of the very first tool, the user interacted with and made modifications over time. Today we need to account for users when creating a car, a road, a house, a Web site, an Intranet, a bomb, whatever it is UCD should involve the users from the beginning to the end and even after. Additionally, the prodcut or interaction should be tested in the real world, and by "world" I mean in all markets, what works for the Netherlands might not work for Jamaica. I remember the first NEW car I ever bought, a silver 1999 VW Jetta, so here I am happy and joyous in my new car until I back out of a parking spot and pull my bumper off in the process. I'm thinking "what did I do wrong?" Nothing Volkswagen didn't test the height of curb stoppers in the USA (well that's my theory anyways). The test would have been very easy, take that Jetta out for a spin to the nearest 7-Eleven in the USA.

In my model I propose the following activities for UCD:
  • Identify the need for a particular product or service and who will use it.
  • Conduct research by interviewing potential users even non users can shed some light "why aren't they going to use it?" maybe with a better design they would. Compare these needs with the business requirements.
  • Develop the solution, this will become more defined as the item goes through many iterations of sketches, mock ups, ideas, feedback, revisions, and testable solutions.
  • Test it
  • Revise it
  • Test it
  • Revise it
  • Test it
  • Launch it
  • Test it
  • Revise it
  • Test it
  • Relaunch it