The Visual Display

Introduction
Data graphics visually display mcasured quantities by means of
the conbined use ofpoinrs, lnres, a coordinare system, numbcrs,
symbols, words, shading, and color.
The use ofabstract, uon-reprcscntational pictures to show numbers
is a surprisingly rccent invention, perhaps because of the divcrsity
of skills required-rhe visual-anisdc, empirical-statistical, and
mathematical. It was not until r75o-r8oo that sratistical graphics_
lengdr and area ro show quantity, time-series, scarterplots, and
multivariate displays were invented, long after such triumphs of
mathematical ingcnuity as logarithns, Cartesian coordinates, rLe
calculus, and the basics ofprobabiLity theory. The remarkable
William Playfair (1759 t84) developed or improved upon nearly
:ll thc fundamental graphical designs, seeJ