Creating graphs to communicate your findings

After collecting and analyzing data, you may want to communicate your findings in the form of a graph.  How can you create graphs to convey your findings effectively?  (Hint:  Opening the Chart Wizard in Excel is NOT the first step!)  Here are some guidelines:

1)  Decide what variables, relationships, and/or comparisons you want to display in your graph.

2)  Decide what you want your graph to look like.

Below are examples of some common types of graphs.  What types of data are represented in each graph?  What relationships are shown in each?

Bar graph:

Scatterplot (with or without a best-fit line):

Line graph:

3)  Sketch what you want your graph to look like.  Be specific.

4) Now that you have decided what variables and relationships you want to display and what your graph should look like, use Excel's Chart Wizard to create your graph.

Helpful hints for graphing with Excel:

• Unless you are plotting raw data (i.e., in a scatterplot), you will need to summarize your data before creating your graph.  Helpful summary statistics include mean, standard deviation, and standard error.  In creating your graph, direct the Chart Wizard to use these summary statistics.

• The default settings in Excel's Chart Wizard often don't produce the most effective graph styles.  Once you've used Excel to create a rough draft of your graph, right click on various parts of the graph and use the options shown to refine how your graph looks.  Your goal is to use Excel to create the graph you originally sketched out.

• Remember to use descriptive axis labels, including units where necessary.  Use a legend only when it helps to explain what the graph is showing.

• Keep the focus of your graph on the relevant information by avoiding unnecessary colors, dimensions, gridlines, etc.