CLEAR, DISCERNIBLE GRAPHS START WITH PROPER TERMS AND LABELING. An easily interpreted graph uses standard fonts, consistent labels and terms. The key elements of labeling include terms, labels, title & font. 

Use all the same terms and labels to describe the contents of your graph. A consistent use of terms and labels in agreement with the title will keep the reader focused on the purpose or intent of the graph.

The first example of consistent labeling can be viewed in the graph above. The word "WOMEN" describes the subjects in the title and in the legend. This is a "Good Example" of consistent labeling and terminology.

Click on the red, "Poor Example" button. The word "WOMEN" is used in the title, but in the legend "females" is used to describe the subjects. WOMEN describes the subjects in "Height. . ." (or Y axis) and "Weight. . . "(or X axis).
Notice in the "Good Example" that the "Weight of Women" label reads vertically along the Y axis. On the "Poor Example" the label for "Weight of Women" is improperly placed at the top of the Y axis.

A graph title is a signpost designed to answer the reader's specific questions. The "Poor Example" does not explain the graph's content. The "Good Example" quickly gives the reader the answer to "What is this graph is demonstrating?"

When you design a graph keep the user in mind. A graph that is easy to read will be understood by the user without misinterpretation 

Select a font for its legibility. Fancy fonts, like Script or Italics , are difficult to read. This type of font distracts the reader from the graph's information.

"To See Good" fonts click on the green button. Notice the blue words clearly label the segments. A standard font like Times Roman or Sans Serif is quickly discernible.
"To See Poor " fonts click on the redbutton. This poor example used a Script font (displayed in red). Notice how much longer it takes to read the pie graph labels.

Kosslyn, Stephen M.,(1994) Elements of Graph Design (pp.63-104) W.H. Freeman and Company.

Valeri Anne Paul