Algebra
in the Media:
Using
Graphic Representations to Model Media Events
Overview:This is a lesson plan that would last 2-3 class periods of one hour each. Students will learn the relationship between graphing in algebra class and graphs in real life settings portrayed through the media. Students will then learn to manipulate graphs in order to support their own conclusions about the data. This will increase their media literacy by teaching how to distinguish misleading graphs.
Targeted at 8th-10th grade algebra students: This activity is targeted for 13-16 year olds who are exposed to newspapers, magazines, commercials, news reports, and other media sources. Students should be in algebra class and have a basic understanding of graphing and different types of graphs. Students, on average, will see graphs as documents that tell the truth and need not be questioned.
Statement of Objectives:
NCSCOS and Competency Objectives
The student will be able to:
Learning
to interpret Graphs in Real Life Situations:
*Note to Teacher*
Use this section first in a whole-group
setting--we suggest overheads or handouts of the graphs. Have
the class answer the questions accompanying each graph. The answers
are only examples of the type of answer that is desired.
Optional homework for the first
day (individually): Bring in a graph that relates to your life.
Answer the questions, "Why is this graph important?" "How does this
graph relate to your life?"
The focus of this section is to:
What is this graph about?
This graph explains how many Americans in a survey think that protecting the environment is more important than developing energy supplies. How does protection of the environment and development of energy
supplies relate to you?
Is this graph helpful in understanding the subject? Why or
why not?
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What is this graph about? What does the graph mean by "downsizing"?
This graph explains that many companies in our region of North Carolina are "downsizing" or reducing their number of employees by cutting jobs. How could the information in the graph affect your life?
Is this graph helpful in understanding the subject? Why or why not?
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Misleading
Graphs:
*Note to Teacher*
Use this section next to show that
graphs with important information are sometimes misleading. This
is also a whole-group activity initially. Show the class the differences
in how each graph is misleading (overhead or handouts) and answer the questions
together.
Optional Activity or Homework:
In small groups, find graphs in magazines, newspapers, on the internet,
in commercials, or on news broadcasts and use the appropriate technology
to capture the graph on a piece of paper, or videocassette. Have
each group present their graph and explain why it is misleading.
The focus of this section is to:
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How do you know which point on the graph represents which person?
Note that the Height is the x axis and the age is the y axis. You use the combination of the person's visible age and height to find the point that best approximates them. Why would this graph never be in a newspaper or on T.V.?
Could this graph be helpful in another situation?
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But some graphs are inaccurate and misleading. There are many ways this can happen:
What is this graph about and what does it have to do with you?
This graph is about Lucent's earnings since 1996. Lucent is a major telecom company that makes phones, computers,etc...cheaper and better than most other companies. On first glance, have the earnings changed lately?
Is the y axis continuous and consistant?
What is this graph trying to trick you into believing?
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What is this graph about and why is it relevant to you?
This graph is about the numbers of people in the United States who get cancer. I am a person in the United States who could get cancer. On first glance, do more women or men get cancer? Is that true
after a closer look?
How is this graph tricking you?
How could we fix this graph?
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What is this graph about and how does it relate to you?
This graph shows the changing prices of crude oil. America uses crude oil to produce energy in many ways including to make gasoline for our cars. Why do the barrels for 1973 and 1974 look so little and the graphs
for 1978 and 1979 look so big?
How are they trying to trick you?
Who would try to trick you in this way?
How can you make this graph accurate?
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What is this graph about?
Itch Relief by using Lanacane. What is the graph trying to tell you?
How much better is Lanacane?
How is this graph trying to trick you?
Who would try to trick you?
How can you graph this subject fairly and informatively?
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What is this graph about and how does it relate to your life?
The graph is about the things that influence the quality of my life. What influences the quality of your life the most according to the
graph?
What does that mean?
Do we know what the graphers ment by "Lifestyle" or "Genetics" or
"21.0%" or "10.0%" or do we have to make stuff up that explains each of
the quantities in order to interpret this graph ?
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Learning
to Graph From Perspectives:
be able to graph any data set from
any relevant point of view using a journal of environmental science set
of data and...creating correct and misleading graphs
*Note to Teacher*
THIS SHOULD BE DONE IN SMALL GROUPS
We have seen how bar graphs, pie charts, histograms,
scatterplots, and line graphs can be used in the media. We are going
to focus on line graphs and scatterplots in the activity since that is
what students are learning in Algebra. Specifically, we are going to fit
data points to a linear model in several different ways. This skill
should have been taught in Algebra class.
Since after graphing this set of data, students would realize that
people get cancer without even being exposed, they should realize that
the Journal of Environmental Health would want to make it appear that all
the people in the area (or a much higher percentage) got cancer from the
Atomic Energy Plant. To do this, the Y-axis should start at one of
the data points with the lowest y value (not starting the y- axis at zero)
which would make the graph seem to say that anyone who is not exposed will
probably not get cancer and anyone who is has a greater chance of getting
cancer. The graph's y axis should probably be in cases of cancer
per 100,000 residents (written in small print under the graph) so that
the number of people with cancer will appear to be more than it actually
is. In the case of the Atomic Energy Plant, the y axis should start
at zero to show that even with no exposure (x=0), 115 people will still
die from cancer per 100,000. Such a graph will make deaths
from hazardous waste look relatively small. The atomic energy plant
could also want to change the # of deaths from cancer per 100,000 to the
% of deaths from cancer because those numbers would look smaller and make
the energy plant look better.
The actual line of best fit for this data is y=9.27386419x + 114.681626.
This means that with an exposure of zero (no exposure) 115 people will
still die of cancer per every 100,000 and for every increase of one in
the exposure index(like from an index value of 1 to 2, or 8 to 9, etc...there
will be a constant rate of increase of approximately 10 more deaths per
100,000 people.
[Data contributed by Dr. Mary Beth Searcy, Appalachian State University]
The table of data below was taken
from an article in the Journal of Environmental Health, May-June 1965,
Volume 27, Number 6, pages 883-897. The article explains that the
Hanford, Washington, Atomic Energy Plant has been a plutonium production
facility since World War II. Some of the wastes have been stored
in pits in the same area. Radioactive waste has been seeping into
the Columbia River since that time, and eight Oregon counties and the city
of Portland have been exposed to radioactive contamination. Research
was conducted to determine what correlation existed between the area residents'
exposure to the radioactive contamination and deaths from cancer.
The table lists the number of cancer deaths per 100,000 residents for Portland and the eight surrounding counties. Also provided is an index of exposure that measures the proximity of the residents to the contamination. Use the information that you have learned about how people can use graphs to manipulate a data set. Make a graph for each portion of the assignment. Include a justification for each graph and how it should be used in popular media to convey the information it portrays.
(1) Make a graph that the Journal of Environmental Health would want to publish.
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Extensive
Free Data Sets:
*Note to Teacher*
These Data Sets are appropriate for practice in data
analysis, quizzes, or tests.