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NTTI Lesson: Sample This
SAMPLE THIS
Grades 4-6
This lesson combines media literacy skills with statistical
research. Students will gain a greater understanding of how statistical
samples are conducted by taking polls of specific populations. These polls
will be expressed in graphs, which will be compared with the same questions
asked of other populations.
Math Talk# 103: The Perils of Polling: Conducting Surveys
Students will:
- suggest better sample taking methods for the two skits featured in
the program.
- poll specific populations and represent the data they have come up
with during their polls in a graph.
- present their groups" findings in front of the class.
- compare the various groups' graphs with each other and record their
inferences about the variations and similarities in the graphs.
- make inferences about sampling methods performed by professional poll
takers.
- paper
- pencils
- calculators
- poster sized paper to draw graphs - one per group of 3-4 students
Several days before this activity, have students record statements
they hear in advertisements about people expressing preference for a product.
Example: "9 out of 10 dentists prefer this toothpaste over other toothpastes."
Explain to students that often sampling methods are not representative of
the entire population. Discuss with the class what it means for a sample
to be representative of the entire population.
Emphasize that students are to watch the following video segment
and record why the mayor's poll taker and the coffee poll were not representative
of the entire population. In addition, students are to make suggestions
about better sampling methods which could have represented the entire population.
Segmented viewing and the pause feature will be used during
this video to allow students time to react and communicate their observations.
BEGIN viewing the video at the start of "The Perils of Polling".
PAUSE after the mayor tells the poll taker for the second time that
"Once again your sample isn't very representative of the population
of all the voters." Allow students to write into their math journals
or on a piece of paper a description of the problem with these sampling
methods and what could have been done to correct the problem. Discuss their
suggestions as a whole class.
RESUME viewing the video. PAUSE the video again after the
manager of the company has written down and stated that of the 150 people
he employs only 13 people voted. The last statement should be, "Exactly
the case your honor. The sample was totally biased." Have students
describe the problem with this coffee break sampling method and how a more
representative poll could have been taken. Continue viewing the video to
the end of this program.
This lesson can be complemented by an awareness lesson of how
advertisers use such sample methods for their purposes. Refer to the statements
students have collected before the lesson. Elicit from students how such
statements could have been made without adequate representation of the entire
population.
Explain to students that you would like for them to see for themselves how
polling various samples can affect the outcome of a poll. Announce that
each group of students will ask the same question of different population
samples.
Assign each group of students a different population to poll. For example,
one group may only poll adults, another group may only poll kindergardeners,
another group may only poll boys of a certain age, while yet another group
may only poll girls of a certain age. Each group will ask the same question.
For example one such question which the entire class could ask may be: What
is your favorite TV show?
Have each group ask a specific number of people. After they have done so,
the groups are to organize their data and create a graph of their results.
For the sake of ease of comparing the various graphs all the groups may
choose to represent their findings with the same type of graph.
Upon completing their graphs, each group is to present their findings in
front of the class. After each group has presented their findings, display
the various graphs in a prominent place, and elicit comparison statements
from the students. Record what differences and similarities they have observed
in the various graphs. Discuss why such differences as well as similarities
may be possible, and if they think that the various populations are representative
of the entire community or our entire country.
Report your classes' findings to the local newspaper for the
national networks using the Internet.
Have students pose the same question to a specific number of
people in their community. Emphasize that their poll should be representative
of the entire population.
Drama:
Have students take another poll that intentionally represents just a small
fraction of the population. Then, have them create a commercial which uses
these findings to its advantage.
Lesson Plan Database
NTTI
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