8 Displaying Data
Textbook Chapters (or similar texts)
Videos
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Inquiry-based Activity: Graph misleaders
Introduction: In both scientific and popular media articles, data are often presented in the form of graphs. However, while students often assume that building graphs is a science, it can be imprecise. Less often, people can be outright trying to lie with their graphs. In this activity, students will themselves build graphs designed to tell specific stories. By playing the role of graph-manipulator, students will gain a better understanding of what they should be looking for when evaluating and interpreting information.
Question to pose to students: Can you successfully use a perfectly unbiased data set to tell a particular story?
Students form a hypothesis: (assume that that they’re up for the challenge…)
Students test their hypotheses: All students receive the same data set. Within this data set is the mean weight of a town over a period of time. In the time period of the data set, a chocolate factory was built in the town. Three groups of people would now like to use the data set for their own purposes. (1) The chocolate factory would like people to believe that the chocolate factory did not lead to any negative changes in the weight of the townspeople. (2) A city councilmember who opposes the factory would like people to believe that the chocolate factory did lead to weight gain for the residents. (3) A scientist is interested in just knowing the truth. Students should get into groups and are then assigned a role (chocolate factory, councilmember, scientist). Based on their role, students should make a graph based on the data set that tells the story they want. They can use any tool available to them – changing the type of graph used, the x or y axes, cherry picking, etc.
Do the students’ hypotheses hold up?: Have students get into larger groups such that each larger group has one of each role (that is, each large group has a smaller group that played the role of chocolate factory, councilmember, and scientist). Their goal is to try and convince the other small groups that their position is correct, based on their graph. Have the students within each larger group vote on which graph is most convincing.
Note: It’s likely that the “scientist” graph will receive few votes. That is okay, and can be used as a talking point for why it is hard for unbiased sources to get their message (or lack thereof) across.
