This paper provides a listing of possible metaphors to use to conceptually make user interfaces more intuitive.

The taxonomy:

1. Orientation- explains a concept in terms of space.

2. Ontological- explain concepts in terms of categories and agreed naming conventions. The authors describe this as making something an object.

3. Structural- reveal the nature of something by comparing it to the structure of some other concept.

Process & Element (Sub category of Structural)

Process- explains of some aspect of system functionality works.

Element- a perceivable aspect of the user interface.

4 Metonymy- A thing that refers to some piece of the system. (an icon for instance).

Conventional: metaphors already used by the target audience without thinking.

Novel: a metaphor that is not conventional.

Entailments: a description of one thing the signified implies about the signified.

Heuristics:

1. Conventional metaphors: know the structure and clearly indicate which standard metaphoric entailments are not applicable

2. Novel metaphors: clearly define all entailments that are valid.

3. Use as many entailments implied by the metaphor as possible.

4. Orientation metaphors: make sure they fit into the conceptual framework defined by that orientation

5. Use as few process metaphors as possible to gain good coverage of the system functionality.

6. Base every element metaphor on a process one.

7. Apply the users metaphoric world as deeply as possible to counter the problem of the subjective nature of metaphor.