We have experiences woven into technology ranging from 0-Dimensions involving the realm of sound, all the way to 3-Dimensional space in which overlaid objectivity heightens what we perceive.
Understanding these experiences as humans intertwined into the realm of technology, involves a host of various sciences and areas of thought.
This is not to say that other areas of a User Centered Strategy are not important, but the gravity of doing a User Persona and a User Journey can be positively felt through out a project as it impacts who the intended use encapsulates. Likewise the positive impact of group consensus over UI Layout, and the effectiveness of approved visual language kindles what is typically referred to as fuzzy-design-logic into clarity.
by Damon Sanchez