Hints on Using Excel for Graphing

"We have powerful tools that can make our work look powerfully ugly!" Thomas Wolff, Associate Dean of Undergraduate Studies, College of Engineering, Michigan State University

If you are graphing data, clearly label your axes on the graph; include units, and point out where the zero point is (if it is on the graph). If more than one curve or line is included, make sure you indicate which curve represents what with some sort of legend. Use multiple colors, solid lines and dashes, or different symbols to differentiate. Graphs are usually constructed with the independent variable (what you are changing) on the horizontal axis, and the dependent variable (what you are measuring or the affected quantity) on the vertical axis. Draw a curve (or a line) through your data only if you are sure that is the form that is suitable for your data. It is not a good idea to simply connect dots. As a general rule of thumb, the data should be left as markers, whereas a curve (or line) represents the trend of the data, or in many cases, a model.

Throughout the semester I will work with you to present your data in a professional manner. As a beginning, take a look at the analysis of data below.

Default Settings in Excel

Better

0	0.1
1	9.3
2	18.3
3	21.3
4	22.7
5	29.3

Data

x	y
0	0.1
1	9.3
2	18.3
3	21.3
4	22.7
5	29.3

Use labels and lines to communicate and present your data.

This is the default graph.

Which one would you put in your lab report?

Here, I used the default for inserting a linear trendline, with the option to include the R² value and the equation.

An extra minute was spent improving the presentation of the data. Always strive for excellence!