Introduction

Problem: analyzing data a significant problem

• Large, complex, multivariate data sets quite common
• Ability to effectively analyze increasingly strained

Solution: draw a picture!

• Visualization provides a qualitative tool to facilitate analysis
• Used to focus analysis, identify patterns and outliers
• Hard to quantify what is interesting (``I'll Know it When I See it (IKIWISI)'', Ward)
• Need interactivity for exploration (``Overview first, zoom and filter, then details on demand'', Shneiderman)

Problem: what to draw?

• Glyphs (aka icons) are popular for conveying information visually.
• Data dimensions (variables) are mapped to attributes of a shape or symbol.
• Variations, clusterings, and anomalies readily perceived.
• Large number of data dimensions can be incorporated.

Problem: Where do you put it?

• Position attribute can be very effective in communicating data attributes.
• Good for detection of similarities, differences, clustering, outliers, or relations.
• Lots of strategies exist.