Constructing Rules
The following are some general rules that should be observed while constructing diagrams:
1. Every diagram must be given a suitable title. The title must convey in as few words as possible as the main idea is that the diagrams intend to portray. However, the brevity must not be secured at the cost of clarity or omission of essential details, the title may be given ether at the top of the diagram or below it.
2. The proportion between width and height must be maintained, if either the height and width is too short or too long in proportion, the diagram would give an ugly look, while there are no fixed rules about the dimensions, a convenient standard as suggested by Lutz in the book entitled the ''graphic presentation'' be adopted for general use. The modifications may, no doubt, be made to accommodate a diagram in the space available.
3. The Selection of scale showing the values must be in even number or in multiples of five or ten, e.g. 25, 50, 75, or 20, 40, 60, odd values such as 1, 3, 5, 7, must be avoided. Again no rigid rules can be laid down about the number of rulings on the amount scale, but ordinarily it must not exceed five. The scale must also specify the size of the unit and what it represent; for e.g., million tones, number of persons in thousands, etc. all lettering must be easily readable without turning the chart up and down.
4. The Footnotes in order to clarify certain points about the diagram, the footnote may be given at the bottom of the diagram
5. Index illustrating the various types of lines or different shades. Colors must be given so that the reader can easily make out the meaning of the diagram.
6. Neatness and cleanliness: The diagrams must be absolutely neat and clean.
7. Simplicity: The diagrams must be as simple as possible so that the reader can understand their meaning clearly and easily. For the sakes of simplicity, it is very important that too much material must not be loaded in a single diagram otherwise it may become too confusing and prove worthless.