Iterative Usability

When Kent Beck defined Extreme Programming, he used the practice of Open Workspace to promote continuous usability. That is, by having customers of a system sitting beside its developers, it becomes possible to have continuous, face-to-face feedback on the system, including how usable it is. This concept is inspired from the Participatory Design work of Kristen Nygaard, who was a founding father of the object-oriented movement.

Usability gurus have since evolved concrete practices to do Iterative Usability. In recognition of this, Industrial XP breaks out Iterative Usability as its own practice.

Personas  

A Persona is an fictitious person who represents a kind of user of a system. By defining the preferences and computing habits of a persona, we can consider a Persona's needs when evolving a system.

Not every XP project needs to define personas. Typically, projects with lots of screens make sense for defining personas, if the representative users can't be on-site.

Personas are often associated with stories during the practice of Storytelling. By associating personas with stories, we consider what features are needed by each persona.

Usability Testing

While some do usability testing upfront, before a project begins, others do usability testing iteratively, as a system evolves. IXP favors iterative usability because our planning process allows plans to quickly change in response to organizational needs. If you create usability test mock-ups of screens that never get programmed, you have wasted time and energy.

Further Reading