Comments on Creating Graphs

A good graph should exhibit the following characteristics.

1. The graph should possess a neat appearance.
   
2. The title should summarize the type of data being presented, and if possible, describe the type of test and specimen used in the experiment.
   
3. All scales should be clearly labeled. You may use symbols in conjunction with descriptive labels, but do not use symbols alone.
   
4. All curves should be labeled. If there is more than one curve, you may use a legend, otherwise the title should suffice.
   
5. Make logical scale choices. The scale should be easily read; ideally, minor and major divisions should be expressible as 1 × 10ⁿ for positive and negative integer values of n but the use of 2, 5, and 2.5 × 10ⁿ is also acceptable.
   
6. Use different symbols for different curves. Distinction between two or more curves and data sets should be made on the basis of the shape of the symbols and line styles used.
   
7. Start scales at zero, if possible (and practical).
   
8. Colors should be chosen to insure that all information will remain intact if the graph is photocopied.
   
9. Margins should be sufficiently large to allow for binding of reports.
   
10. Label significant points or features on curves.
    
11. Plot the dependent variable vs. the independent variable (follow accepted practice).
    
12. Sketch the loading situation. This should accompany the graph and if sufficiently simple, and if space is available, it can be located on the graph. However, be careful not to give the graph a cluttered appearance.
    
13. DO NOT show points on a theoretical curve; simply show the curve and give the equation. Likewise, DO NOT connect the points on an experimental curve; simply show the data points that were obtained during the experiment.
    
14. The equation of a curve (least squares fit) should be shown on the graph, or on a page accompanying the graph, if it has been obtained. If only part of the data was used to obtain the equation, the part used should be clearly identified. Use the appropriate symbols and numerical values in the equation, not the generic y=mx+b.
    
15. All graph titles, labels etc. should be oriented such that they can be read from the bottom and/or the right side of the graph; and the bottom of the graph should be parallel to either the bottom or right edge of the page.