User states and contexts is a use-modelling tool for conceptualizing, designing, and evaluating the ability of a design to be consumed and operated by users in a wide range of states and contexts.
A user states and context map can demonstrate needs that are represented by a particular persona, or that of a collection of personas. The map can also be used to consider how states and contexts can change in the short term (e.g. on a daily basis) or the long term (e.g. over a lifetime).
By demonstrating the many states and contexts a user can be in at any given time and in any given situation, the map presents a bigger picture. It describes the broad and ever-changing needs of a single user, and also allows a comparison of the needs of multiple users. In this way it can reveal patterns, interesting outliers, or commonalities in needs that might not otherwise be obvious.
Needs that are commonly met are placed in the middle, and needs that are not well met are placed toward the edge. This demonstrates that the needs of users "on the edge" are greater in number, as well as the phenomena that by meeting edge needs, you also meet the mainstream needs of the middle.