A Manual of Design and Construction, 1938, prepared by Committee on Standards for Graphic Presentation, under procedure of American Standards Association, with The American Society of Mechanical Engineers as sponsor body.

TIME-SERIES LINE CHARTS

The "time-series line chart" is the type in which values of a time series are plotted on a coordinate surface ond the points joined together successively to form a continuous line or "curve." The line chart has a wide range of application and in most cases is relatively easy to construct and maintain.

A. THE LINE CHART SHOULD GENERALLY BE USED:

1. For series where there ore many successive values to be pictured.

2. Where several series ore shown for comparison on the same chart.

3. For close reading or interpolation.

4. When the emphasis should be on the movement rather than on the actual amounts.

5. When the chart is to be used for the projection of trends.

B. THE LINE CHART MAY NOT BE THE BEST TYPE:

1. Where there are relatively few plotted values in the series.

2. Where the emphasis should be on the change in amounts rather than on the movement of the series.

3. To emphosize the difference between values or amounts on different dotes.

4. When the movement of the doto is extremely violent or irregular.

5. When the presentation is designed for popular appeal.

CURVE CHARTS

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