# Introduction

The only new thing in the world is the history you don't know.
Harry S Truman
quoted by David McCulloch in "Truman"

The graphic portrayal of quantitative information has deep roots. These roots reach into histories of thematic cartography, statistical graphics, and data visualization, which are intertwined with each other. They also connect with the rise of statistical thinking up through the 19th century, and developments in technology into the 20th century. From above ground, we can see the current fruit; we must look below to see its pedigree and germination. There certainly have been many new things in the world of visualization; but unless you know its history, everything might seem novel.

## A brief overview

The earliest seeds arose in geometric diagrams and in the making of maps to aid in navigation and exploration. By the 16th century, techniques and instruments for precise observation and measurement of physical quantities were well-developed- the beginnings of the husbandry of visualization. The 17th century saw great new growth in theory and the dawn of practice- the rise of analytic geometry, theories of errors of measurement, the birth of probability theory, and the beginnings of demographic statistics and "political arithmetic". Over the 18th and 19th centuries, numbers pertaining to people-social, moral, medical, and economic statistics began to be gathered in large and periodic series; moreover, the usefulness of these bodies of data for planning, for governmental response, and as a subject worth of study in its own right, began to be recognized.

This birth of statistical thinking was also accompanied by a rise in visual thinking: diagrams were used to illustrate mathematical proofs and functions; nomograms were developed to aid calculations; various graphic forms were invented to make the properties of empirical numbers- their trends, tendencies, and distributions- more easily communicated, or accessible to visual inspection. As well, the close relation of the numbers of the state (the origin of the word "statistics") and its geography gave rise to the visual representation of such data on maps, now called "thematic cartography".

Maps, diagrams and graphs have always been (and continue to be) hard to produce, still harder to publish. Initially they were hand drawn, piece-by-piece. Later they were etched on copper-plate and manually colored. Still later, lithography and photo-etching, and most recently, computer software was used, but graphic-makers have always had to struggle with the limitations of available technology- and still do today. Some note-worthy places in the history of visualization must therefore be reserved for those who contributed to the technology.

Most recently, advances in statistical computation and graphic display have provided tools for visualization of data unthinkable only a half century ago. Similarly, advances in human-computer interaction have created completely new paradigms for exploring graphical information in a dynamic way, with flexible user control.

While most of the recent contributions listed here relate to the visual display of statistical data, there has also been considerable interplay with advances in information visualization more generally, particularly for the display of large networks, hierarchies, data bases, text, and so forth, where problems of very-large scale data present continuing challenges.