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# Charts and Diagrams by Cathy Spalding

Visual aids can also include any type of charts and diagrams. While these are considered to be visual images, they are simply a way of representing data in a graphic form. Many of your hard facts will become more interesting if they are presented in this way. These graphic forms are a simple way to display comparisons between different data or between different periods in time.

## Choosing a Type

There are many different types of charts, diagrams, and graphs. Certain types are used more often in research papers. One of these is the frequency polygon. This is also referred to as a line chart. A frequency polygon is used to show comparisons over time between different items.

Another type is the histogram, also referred to as a bar chart. This also shows comparisons and can contain many different items. Performance is shown as a solid bar instead of the single line used for a frequency polygon.

Pie charts, which are the ones that most of us are most familiar with, show the proportion of parts to a whole. The parts are shown as percentages.

The pictograph is not commonly used in research papers. This chart is so named because it includes a picture in the form of a drawing to further illustrate what is being compared. The picture is generally shown on a bar chart.

If you need to illustrate the steps that are taken to perform a certain task or to carry out a sequence of events, you might want to use a flow chart. This depicts each step and where it falls in the process. For example, you could use a flow chart to show the steps you should take to write a research paper.

A column chart is very similar to a bar chart, but it is usually used to show two or more different items at specific stages. It could also show comparisons between these items.

To show how different tasks, events, or ideas compare, use a Venn diagram. A Venn diagram usually shows three separate tasks that overlap which illustrates what these tasks have in common and how they differ.

Use a cycle diagram when you want to show a process that is part of an ongoing cycle. These are commonly used to display life cycles. There are various steps along the process, but they all return back to the beginning, where the cycle starts again.

A final commonly used diagram is the pyramid diagram. This is used to represent data that builds on a foundation. Typically, the top of the pyramid represents something more desirable than the bottom. (You are probably familiar with the food pyramid from grade school, which illustrates the basic food groups and how much of each type we should eat.)

## When to Use Them

Charts and diagrams are ideal when you have large amounts of data to convey. Instead of simply listing all the data, you can show it visually. This allows readers to see relationships and processes where before they saw only numbers and information. Often the biggest question is not whether to use charts and diagrams, but which type to use. There are usually only one or two types that will best fit the information you need to convey. It may take some experience to figure out which type of visual aid works best for which type of data. Any of these charts and diagrams can be included on a page of text. Avoid splitting any of these types of figures into two parts. If you cannot fit the entire figure on the page you began it on, see if you can place it elsewhere in the paper. It may even need a page of its own.