A good persona description is not a list of tasks or duties; it is a narrative that describes the flow of someone’s day, as well as his or her skills, attitudes, environment, and goals. A persona answers critical questions that a task list does not, such as why the persona wants to use the product, and whether they can focus on one thing at a time, or experience lots of interruptions.

It is preferable to keep the number of personas required to illustrate key goals and behaviour patterns to a minimum. There is no magic number, but evidence from experienced and successful designers suggests that between four and eight personas would usually suffice to provide a focus for a single product.

When designing personas, focus first on the information that is critical for design, such as the behaviour patterns, goals, environment, and attitudes of the persona. Then add one or two personal details and facts, such as what your persona does after work. Add life to the persona, by giving a few examples of things that the persona never gets time to do. With a little personality, personas can become useful design targets.