chapter  2
Graphical Analysis
WithRalph B. D’Agostlno
Pages 56

This chapter illustrates the use of graphical techniques as they relate to goodness-of-fit problems. For goodness-of-fit problems they can be used in at least two ways: As an exploratory technique and In conjunction with formal numerical techniques. Graphical techniques as presented here are simple tools which can be implemented easily with the use of graph paper or simple computer programs. The chapter concerns itself with simple to use graphical procedures involving arithmetic or log graph papers in conjunction possibly with simple arithmetic and table look-ups, or else with procedures involving readily available special probability plotting papers. At times the interest is not in describing the entire distribution of a variable but rather only one or both of the tails of the distribution. Mathematically, this is equivalent to assessing the thickness of the upper tail or finding a mathematical model which "fits" the upper tail. Elaborate sophisticated computer graphics are not needed to produce probability plots.