Visualization Lesson Plan Critique
The lesson plan I’m reviewing is found at: http://www.ms.uky.edu/algebracubed/lessons/Graphs.pdf
This is a nice idea for a lesson plan. The plan is targeted at 7th graders and explores the area of graphs and how they can be manipulated to mislead.
I think this is a stimulating topic to explore. Covering this topic will deepen student understanding of visualization techniques. It has real world connections which should pick up student interest. Also, it deals with deviousness and manipulation, unusual topics for math class that can provoke a visceral response.
The lesson comes with:
1. An outline of various practices that can make a graph misleading,
2. Internet materials with examples of misleading graphs and explanations of why they are misleading,
3. A couple of examples of misleading graphs taken from the internet to be used as worksheets,
4. A project where students create their own misleading graph using real data.
It seems like a well constructed lesson. First the concept of misleading graph is explained and real world examples are given. Then students are given worksheets where they have to identify the types of problems exhibited in various graphs. This is their chance to check their understanding of the material. Finally, they create their own misleading graph, which is a good way to evaluate and reinforce the material in the lesson.
There are six links to the internet provided in the lesson. The first 3 are meant to be brought up and projected as part of the lecture, and the last three are references to material provided in the lesson worksheet.
Unfortunately, the first two links, which are meant to be examples from news sources of data manipulation, are broken. CNN changed its graph after the report from mediamatters and the links to the old and new charts do not work. The link to the second site, which was to demonstrate a variety of incorrectly done graphs, is broken. The third link, at http://thinkprogress.org/2006/03/15/aol-chart, actually shows a dishonest graph, not just misleading but a misrepresentation done by comparing two different things without mentioning they are different (and Thinkprogress itself may be dishonest, by providing the chart without the surrounding material. It appears to be soing the same sort of behavior it is criticizing).
The difficulties mentioned above are a lessonin lesson preparation: When referencing a web page for future use, it’s a good idea to create a copy of it and reference that as well.
Ideas for improvements:
Find new examples of misleading graphs from the internet (and save copies of them to an independent site), since the links provided in the lesson are broken.
Add more graphs to the worksheet, there are only two examples to work on, a few more wouldn’t hurt.
For the project, have the students create a misleading graph as well as a well made one with the same data.