Creating Charts and Graphs

Using their own data to create charts and graphs helps students see that each format has its own purpose. Line graphs are used to illustrate change, bar graphs to compare items, pie charts to show how a set of pieces make up a whole, etc. We make choices about which format to use based on what message or information we're trying to convey.

Experimenting with those choices teaches students how form and content relate - that looking at the graphic format tells you something right away about what the author is trying to explain.

For some clear lessons on constructing charts and graphs, take a look at: http://www.fodoweb.ca/education/readtext.asp?txtfile=communications/charts.toc

Constructing charts also allows students to see how data can be manipulated to give different impressions of the same information. This understanding helps them be more critical readers of charts and graphs, asking questions about how the data is being organized and presented.

For an example of how charts can be constructed to convey different impressions with the same data, see: http://www.mste.uiuc.edu/courses/ci330ms/youtsey/lineinfo.html

(Note: Consider, for example, how your impression of the data would change if the second Federal Minimum Hourly Wage chart used five-year intervals on the x-axis instead of 10-year intervals.)