One of the challenges of user experience and interaction design is deciding how to convey your designs to others, whether to clients or to designers and developers. What is obvious to a UX practitioner isn’t necessarily obvious to those in other fields, and UX documentation’s purpose is to communicate the UX design to everyone, not just the UX designer.
UX documentation is not yet standardised in the industry, but there are certain types of visualisation methods that have become commonplace, the most well-known being site maps, wireframes, user journeys and process flows. These aren’t the only methods available, however, and they may not always be appropriate to all circumstances.
A Periodic Table of Visualization Methods provides a good reference to various methods, grouping them into the categories of data visualisation, strategy visualisation, information visualisation, metaphor visualisation, concept visualisation and compount visulation. It also indicates whether the methods are process or structure visualisation, whether they include an overview, detail or both, and whether they illustrate divergent or convertent thinking. Mousing over each method makes an example pop up.