The Elements of Statistical Method (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1912 Excerpt: ...probably being the bar diagram. The size of the number is, in this method, simply represented by the length of the bar. Fre COMPARATIVE PlCTOORAMB quently, the composition of the number is also represented by the shading of the bar as illustrated in Fig. 2. This has the advantage of bringing the whole study into one diagram and the disadvantage that all the sections, except the first, are rendered rather difficult of exact comparison since they do not originate or terminate on the same straight line. The plan may be modified by making a separate set of bars for each group. For the illustration of more complex mathematical relationships, the use of bars is usually insufficient. It is necessary in such cases to resort to figures of two or three dimensions. Fig. 3 represents a comparison of the hourly wage, length of working day, distribution of expenditures of the workers, and number of workers employed in industries A and B. It may be said that, in general, as the number of factors to be compared increases, the accuracy of comparison of some of the groups is diminished. In the illustration, while it is quite easy to compare the number of workers, the Bar Diagrams. Population of Cities by Race and Nativity. hourly wages, and the hours worked per week, both the absolute amounts and the percentage of the income spent for the different items are not easily comparable because of the varying shape of the rectangles or parallelopipeds involved. Another useful variety of pictogram is the circle divided into sectors as shown in Fig. 4. These sectors may be colored or shaded as desired. In the illustra Fig. 3. tion, the size of the circles represents the total cultivated area while the angular dimensions of the sectors show the relative importance of each crop in the ...