This book bridges the gap between computer graphics and human-computer interaction by studying how pictures can be used in computer systems to convey information to users.

One of the overriding concerns is to highlight the relationship between pictures and linguistic representations of information. To reduce the complexity of the topic, a new classification for pictures is defined which focuses on the task that users are to carry out with the help of pictures presented on computer screens. A model for analyzing and influencing the flow of information via pictures is presented and used throughout the book.

Each of the classes of graphics is studied with the help of many illustrative examples to develop methodologies for the use of pictures in dialogue systems.