| This dissertation describes research on the graphical presentation of relational information. It presents theoretical results about graphical languages and a program that incorporates these results.;These theoretical results are incorporated into a graphical presentation program called APT (A Presentation Tool). APT is unique in that its designs are sensitive to both the structure of the information and the output medium. The design process has three parts. First, the information is divided into components, each of which satisfies the expressiveness criterion for a primitive graphical language. Next, effectiveness criteria are used to select the most effective primitive graphical language for each component. Finally, composition operators are used to compose the individual designs into a unified presentation of all of the information. Even though only a few primitives are implemented, APT can synthesize a wide variety of designs that express information effectively.;According to the theory, a graphical language is a set of graphical sentences (such as bar charts, scatter plots, or connected graphs), each of which is a two dimensional arrangement of pixel objects. These languages are evaluated on the basis of two graphic design criteria: expressiveness is an indication of the kinds of relational information that can be expressed in a language, and effectiveness deals with the relative desirability of sentences from alternative graphical languages. A composition algebra is also developed that can be used to systematically generate a wide variety of graphical languages from a small set of primitives. |
