Possibilities and Limits in Visualizing Large Amounts of Multidimensional Data

In this paper, we describe our concepts to visualize very large amounts of multidimensional data. Our visualization technique which has been developed to support querying of large scientific databases is designed to visualize as many data items as possible on current display devices. Even if we are able to use each pixel of the display device to visualize one data item, the number of data items that can be visualized is quite limited. Therefore, in our system we introduce reference points (or regions) in multidimensional space and consider only those data items which are ‘close’ to the reference point. The data items are arranged according to their distance from the reference point. Multiple windows are used for the different dimensions of the data with the distance of each of the dimensions from the reference point (or region) being represented by color. In exploring the database, the reference point (or region) may be changed interactively, allowing different portions of the database to be visualized. To visualize larger portions of the database, sequences of visualizations may be generated automatically by moving the reference point along some path in multidimensional space. Besides describing our visualization technique and several alternatives, we discuss some of the perceptual issues that arise in connection with our visualization technique. to appear in: ‘Perceptual Issues in Visualization’, Springer, 1994.