Transcript Presentation

Group 3: Airplane!
GOALS
•Students will investigate the role of variability
in data collection.
•Students will engage in the hands-on
process of data collection.
•Students will identify sources of error in data
collection and offer methods of controlling
these sources.
Activity Set-Up
• Student materials needed: calculators, paper
• Teacher materials needed:
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Models for folding paper airplanes (as requested)
Instruction and data collection sheet
Measuring tape
Masking tape
• Prior skills required:
– Calculate measures of center
– Make graphs of data
Directions of Activity
1. Each group (about 3 students) must make a
prediction about the distance that a paper
airplane can fly, either radially or as measured
perpendicular to the direction of release.
2. Each group must construct their paper airplane
from their own paper. If no one in the group
can make a successful paper airplane, models
of folding will be provided.
(See www.bestpaperairplanes.com )
The “Zump” Model
Directions of Activity (continued)
3. Each group will launch their airplanes in
repeated trials (as many as possible in a fixed
amount of time or a fixed number of trials set
by instructor). Data will be recorded in a table.
4. Each group will calculate a measure of center
(mean, also perhaps median) for their
distances, and then make a graph on the
board, floor, or computer to represent their
data. The type of graph may be at the
discretion of the teacher and/or students.
Classroom Analysis
• Compare means and graphs of data from
different groups. Key questions:
– How can variability in the measurement of a
single variable be observed in the graphs?
– Why might different groups end up with clearly
different mean flight distances?
• Can the entire class compile its data to
find a single estimate for the mean flight
distance of a paper airplane? Why or why
not?
Discussion
• Students should realize that because each
group had different models and launching
techniques, it is NOT valid to simply gather
data from all groups to get a class
distance estimate.
• The key principle is to identify sources of
variability that could have been controlled
before beginning the activity.
Unintended Variability
• Students should generate a list of sources of
variation between groups, such as:
– Design of airplane
– Angle of launch (may not have even been the same
within a group throughout)
– Distance measured from tip or tail
– Wind
– Experience of group members with airplanes
– Type and size of paper used in construction
– Level of damage to airplanes after repeated trials
Concluding Ideas
• Students should agree that a standardized
launch process would help to minimize variability
and find a more accurate estimate of the mean
flight distance.
• Students should also recognize that variability
still cannot be eliminated, either due to variables
out of man’s control (wind) or to the inherent fact
that planes won’t always fly the same distance
every time.
Next Steps
• In future projects, students can be assessed on their
ability to prepare a procedure that will enable all
data-gatherers to follow an identical process for
experimentation or surveying.
• Issues of sample size and standard deviation can be
discussed later.
• Subsequent experiments (like predicting whether
coins can be rolled down the hall farther than
airplanes can fly) can lead to hypothesis tests for
comparison of two means, and as an opportunity to
demonstrate systematic procedures to avoid
confounding variables.