In the world of Technical Communication, graphs are an excellent way of relaying data, but only if you use them correctly. Today in our Professional and Technical Writing class we were given a set of graphs and asked to point out if the graph covered each of the 5 important characteristics.
- Does it serve a purpose?
- Is it simple and uncluttered?
- Does it present a manageable amount of information?
- Does it meet your format expectations?
- Is it clearly labeled?
As many may think graphs are simple and easy, as we can deduct from our lengthy class discussion, they are not. Depending on your data, the choice between a line graph, pie chart or bar graph can be a difficult one. In addition to the 5 important characteristics, the key steps below can help you to achieve the best graph for your needs. The graphs focused on in this post are those for illustrating numerical information (tables, bar graphs, pictographs, line graphs, and pie charts).
First, I must advise, if you are ever to make a graph, please keep it 2-d. As Mike Markel points out, three dimensional charts can skew the data and appear much different to the reader. A two dimensional chart will communicate the information much better.
Second, know what purpose you wish to serve with your graph, and which graph type will communicate this best. I have seen many people make the mistake of implementing a line graph when it would make much more sense to use a bar graph.
- A table is usually what is used when there is just too much information to convey in any other kind of graph. As tables are often boring and not visually appealing they are the last choice of many, but can be very beneficial when utilized correctly.
- A bar graph can be excellent to compare and contrast relative numerical values of two or more items. Ranging from Grouped bar graphs, to subdivided or deviation bar graphs, there are many different types out there so be sure to choose wisely. Often placed in its own group, a pictograph is very similar to a bar graph. Instead of bars, symbols are used to illustrate statistics and information in which each symbol represents a quantity or numerical value.
- Line graphs are used to show changes over time. “A line graph focuses the readers’ attention on the change in quantity, whereas a bar graph emphasizes the quantities themselves” (Markel). For example, if you would like to display tuition rates at RIT over 10 years you would use a line graph so the reader can see how the amount has changed overtime, whereas a bar graph brings attention to each year individually.
- Pie charts are used to show relative size as part of a whole. Most pie charts are based on a 100% scale, and when I say most, I mean it is rare to find one that is not.
Third, as stated in the 5 characteristics, present your information in an uncluttered matter that is easy to understand and read. When dealing with numbers be clear to state what the number is (money, people, percentage…) and what place value the number is in (thousands, millions…). It is also necessary to label the axis and when dealing with a pie chart make sure it is clear what each slice represents.
Making sure to choose the right graph and convey the information correctly can be tricky, but hopefully with the tips above you will have an excellent graph in no time.
Sources: Practical Strategies for Technical Communication, Mike Markel