According to usability.gov, “A persona is a fictional person who represents a major user group for your site. Personas help you identify major user groups of your Web site. You select the characteristics that are most representative of those groups and turn them into a persona. [...] Using personas helps the team focus on the users’ goals and needs. The team can concentrate on designing a manageable set of personas knowing they represent the needs of many users. By always asking, "Would Jim use this?" the team can avoid the trap of building what users ask for rather than what they will actually use.”
According to Fluid project article, “Personas are a model used to describe users' goals, skills, abilities, technical experience and context. They are detailed descriptions of archetypical users constructed out of well-understood, highly specific patterns of data about real people. A persona is not based on an individual - it is a construct developed through a detailed process, not the result of a search for the "right" individual (see persona creation for more on this). They are used by the design team (and larger project team) to describe, and keep front and center the user(s) for whom the system will be built.”
“A persona is a user archetype you can use to help guide decisions about product features, navigation, interactions, and even visual design. By designing for the archetype—whose goals and behavior patterns are well understood—you can satisfy the broader group of people represented by that archetype. In most cases, personas are synthesized from a series of ethnographic interviews with real people, then captured in 1-2 page descriptions that include behavior patterns, goals, skills, attitudes, and environment, with a few fictional personal details to bring the persona to life” (Kim Goodwin (2001).
Personas will include
In addition:
With a persona sheet in mind, a member of the web design team then could say "well, Joe would do this and think that ...")