Page:Graphic methods for presenting facts (1914).djvu/58

 no necessity of inflicting such cruelty on a reader. Though the circles in Fig. 37, drawn on a diameter basis, exaggerate the ratios, the circles in Fig. 38, plotted on an area basis, make the reader underestimate the ratio. Comparison between circles of different size should be absolutely avoided. It is inexcusable when we have available simple methods of charting so good and so convenient from every point of view as the horizontal bar.

Independent

Fig. 39. Proportion of College Graduates in Different Professions in 1696-1700 and in 1896-1900

Charts of this kind with men represented in different sizes are usually so drawn that the data are represented by the height of the man. Such charts are misleading because the area of the pictured man increases more rapidly than his height. Considering the years 1696-1700, the pictured minister has about two and one-half times the height of the man representing public service. The minister looks over-important because he has an area of more than six times that of the man drawn to represent public service. This kind of graphic work has little real value

In Fig. 37 and in Fig. 38, it would have been better if the year had been given under each circle, with the figures for quantity placed above the circles, so as to follow the standard arrangement of having