Overview

In some ways, a visualization can be considered an internal interface in a problem-solving system that has both human and computer components. A visualization can be the interface to a complex computer-based information system that supports data gathering and data analysis. On the human side, the visualization can act as an extension of cognitive processes, augmenting working memory by providing visual markers for concepts and by revealing structural relationships between problem components. A manager working with a spreadsheet and plotting projections is combining business knowledge with the computational power of the spreadsheet model. The plotted projections are visualizations that enable aspects of the model to be integrated efficiently into the cognitive decision-making process of the manager.

Interactive visualization is a process made up of a number of interlocking feedback loops that fall into three broad classes. At the lowest level is the data manipulation loop, through which objects are selected and moved using the basic skills of eye-hand coordination. Delays of even a fraction of a second in this interaction cycle can seriously disrupt the performance of higher-level tasks. At an intermediate level is an exploration and navigation loop, though which an analyst finds his or her way in a large visual data space. As people explore a new town, they build a cognitive spatial model using key landmarks and paths between them, and something similar occurs when they explore data spaces. But exploration can be generalized to more abstract searching operations. Kirsh and Maglio (1994) define a...