Appropriate and inappropriate uses of graphs

What's Wrong with This Picture?

When students frist begin to use a spreadsheet graphics package (e.g. Microsoft Excel), they will invariably make errors in what graphs they choose and how they set up their data in the graph. It is important to begin a discussion BEFORE they start creating graphs.

CLASSROOM ACTIVITY
To set up this activity, first read the information in the link below or Chapter 9 of Seeing Through Statistics by Jessica Utts, Duxbury Press. Nowlook in the local newspaper for 6 to 8 examples of errors (This will only take a few days of papers. Sad isn't it). Or, you could just use the examples in the webpage. Make transparencies of each example.

In class, ask each student to write down an interpretation of each graph and ask how the information in each graph could be presented better. this is a "What's Wrong with This Picture?" game. Have the students discuss their interpretations in small groups coming up with common rules for creating good graphs. convene the whole class to creat a list of rules for creating good graphs.

As a follow-up, ask students to create a graph of some data of interest for their term portfolio. Some students will still make mistakes, but most of them will do better from having done this exercise.

Using Technology to Create Effective Graphs: Issues to be Considered http://www.coe.uh.edu/insite/elec_pub/HTML1997/ma_host.htm

Examples of Good and Bad Experimental Plots http://www.ruf.rice.edu/~bioslabs/tools/graphs/grapherror.html