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Elizabeth Gutierrez PBI- Indoor Air Quality Project
Monday& Tuesday; Week 4
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PBI:PBI:PBI:PBI: INDOORINDOORINDOORINDOOR AIR QUALITY PROJECTAIR QUALITY PROJECTAIR QUALITY PROJECTAIR QUALITY PROJECT
AUTHORSAUTHORSAUTHORSAUTHORS’ NAMES: NAMES: NAMES: NAMES: Liz Gutierrez
TITLE OF THE LESSON: TITLE OF THE LESSON: TITLE OF THE LESSON: TITLE OF THE LESSON: Review of Measures of Central Tendency & Survey
Introduction
TECHNOLOGY TECHNOLOGY TECHNOLOGY TECHNOLOGY LESSON:LESSON:LESSON:LESSON: No
DATE OF LESSON: DATE OF LESSON: DATE OF LESSON: DATE OF LESSON: Monday & Tuesday; Week 4.
LENGTH OF LESSON:LENGTH OF LESSON:LENGTH OF LESSON:LENGTH OF LESSON: 90 min
NAME OF COURSE: NAME OF COURSE: NAME OF COURSE: NAME OF COURSE: PBI- High School Classroom
TEKS ADDRESSED: TEKS ADDRESSED: TEKS ADDRESSED: TEKS ADDRESSED:
TEKS: 111.23 (11) Probability and statistics. The student understands that the way a set of data is displayed influences its interpretation. The student is expected to:
(A) select and use an appropriate representation for presenting and displaying relationships among collected data, including line plot, line graph, bar graph, stem and leaf plot, circle graph, and Venn diagrams, and justify the selection; and (B) Make inferences and convincing arguments based on an analysis of given or collected data.
(12) Probability and statistics. The student uses measures of central tendency and variability to describe a set of data. The student is expected to:
(A) Describe a set of data using mean, median, mode, and range; and (B) Choose among mean, median, mode, or range to describe a set of data and justify the choice for a particular situation.
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PERFORMANCE OBJECTIVES: PERFORMANCE OBJECTIVES: PERFORMANCE OBJECTIVES: PERFORMANCE OBJECTIVES:
SWBAT… correctly use and understand measures of central tendency such as Mean, Median, Mode, and analyze data by correctly using regression and create and administer a survey. RESOURCES: RESOURCES: RESOURCES: RESOURCES:
•••• The chart comes from http://www.surveysystem.com/sscalc.htm the Survey Size Calculator...
SAFETY CONSIDERATIONS:SAFETY CONSIDERATIONS:SAFETY CONSIDERATIONS:SAFETY CONSIDERATIONS: None
SUPLEMENTARY MATERIALS, HANDOUTS: SUPLEMENTARY MATERIALS, HANDOUTS: SUPLEMENTARY MATERIALS, HANDOUTS: SUPLEMENTARY MATERIALS, HANDOUTS: • Chart (at end)
ENGAGEMENTENGAGEMENTENGAGEMENTENGAGEMENT TUESDAYTUESDAYTUESDAYTUESDAY Time: 15 minutesTime: 15 minutesTime: 15 minutesTime: 15 minutes What the Teacher Will DoWhat the Teacher Will DoWhat the Teacher Will DoWhat the Teacher Will Do Probing QuestionsProbing QuestionsProbing QuestionsProbing Questions Student ResponsesStudent ResponsesStudent ResponsesStudent Responses
Potential MisconceptionsPotential MisconceptionsPotential MisconceptionsPotential Misconceptions After 3 weeks of discussing and
considering various aspects of air quality…
Pose following question to
students…
What can kinds of
changes can we as students and faculty at
_______ school implement in order to improve our
campus air quality?
• Plant more trees • Car-pool • Ride the bus • Eliminate the
busses • Clean the school to
get rid of dust and allergens
• Have more plants in classrooms
• Open the windows in the building
• Change the
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Any ideas or suggestions?
cleaning products used to non-toxic cleaners
Write suggestions on the board…
Any more ideas? • Ride bike or walk to school
• Recycle paper and plastics
• Change the air conditioning filters
• Stop using chemical air fresheners
• Make entire campus a smoke-free zone… including parking lot (parents….)
Assign the following in-class activity… Tell students…
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As a class we have come up with a whole list of
possible changes that we can implement in order to improve our school’s air
quality, but I would like for you all to research what
other schools have done, to see if you get any more ideas. Get on computers and look this up…. If you find any particularly good or interesting things other schools have done, come up and add them to our
list. EXPLORATIONEXPLORATIONEXPLORATIONEXPLORATION TUESDAYTUESDAYTUESDAYTUESDAY Time: Time: Time: Time: 25252525 minutesminutesminutesminutes What the Teacher Will DoWhat the Teacher Will DoWhat the Teacher Will DoWhat the Teacher Will Do Probing QuestionsProbing QuestionsProbing QuestionsProbing Questions Student ResponsesStudent ResponsesStudent ResponsesStudent Responses
Potential MisconceptionsPotential MisconceptionsPotential MisconceptionsPotential Misconceptions Pose the Question…
How possible is it that all or most students, faculty,
and parents will participate in these
• Not very possible • Very possible • Maybe if we
explain the benefits to them
• It depends… some students, faculty,
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changes?? and parents CANNOT implement these changes due to external/extenuating circumstances.
Is there any way to find out whether or not most
would be willing or able to make these changes?
Yes… ask them. No, there’s no way we
could possibly ask everybody! Maybe…
Is there any way to find out without having to ask
EVERYBODY?!
NO. Well, what if we ask
most?
How would we know how many people we would
have to ask to get MOST people’s response?
Just ask a majority.
How would we ask everybody? Or at least a
majority?
• Ask them • We can’t • Conduct a survey
WE CAN CONDUCT A SURVEY??!
When someone has questions that they ask a
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What is a survey?
bunch of people.
A questionnaire that you fill out.
So if we wanted to know if our ideas would actually
be practiced by the students, parents, and
faculty we could conduct a survey?
Yes
How do we create a survey?
You make up questions to ask people and then give
them out.
Tell Students: Take a few minutes to put
together 4 items either from the board or that you came up with on your own that you think are likely to be realistic goals for our
school.
Allow students time to choose/come up with 4 items and write them
down (in their groups).
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Continue discussion/lesson in survey groups… probing questions will be presented to class and teacher will walk around to individual groups. Discussion will be conducted and compared aloud in order to compare findings among groups.
Now what do we do with these questions?
• Pass them out • Ask people to
choose the one they are mostly likely to do
Now back to something we discussed earlier…
How many people do we have to survey in order to get the “majority opinion” or a large enough sample
size?
90% I don’t know.
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Well let’s define some survey terms.
Write the following terms on the board…
• Target Sample • Sample • Sample Size • Representative
Sample Take some time to write down what you think these terms might mean. Discuss student’s responses, address confusion or misconceptions, and talk about correct definitions.
EXPLANATIONEXPLANATIONEXPLANATIONEXPLANATION WEDNESDAYWEDNESDAYWEDNESDAYWEDNESDAY Time: Time: Time: Time: 44440 minute0 minute0 minute0 minutessss What the Teacher Will DoWhat the Teacher Will DoWhat the Teacher Will DoWhat the Teacher Will Do Probing QuestionsProbing QuestionsProbing QuestionsProbing Questions Student Student Student Student ResponseResponseResponseResponse
Potential MisconceptionsPotential MisconceptionsPotential MisconceptionsPotential Misconceptions So if we want the results
of our survey to be • 80% • 99.9%
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representative of EVERBODY at our school how many people do we have to give our survey
to?
Is there a special or magic number or percentage?
• 25% • 5 people • 100 people • 500 people
How did you come up with that number/percentage?
(to each student that offers a suggestion)
• I guessed • It seems like a big
enough number • That’s my favorite
number It seems big enough?
What does that mean? It seems like knowing what that number of people think would
possible be representative of everybody.
These sounds awesome, so for a few minutes let’s consider why we wouldn’t want to survey all the students, faculty, and parents that interact with our school. What are some reasons you may not want to ask
• It would take too long
• It would take too much effort
• It probably wouldn’t be possible to survey EVERY SINGLE PERSON!
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everybody?
Good! The reasons that we “sample” a smaller
group than our population are for all the reasons you
all just mentioned? OR mention/hint at any the
students might have missed!
Reasons: (1) The cost is too high
and (2) The population is dynamic, i.e., the
component of population could change over time.
There are three main advantages of sampling: (3) The cost is lower, (4) Data collection is faster, and (5) It is possible to
ensure homogeneity and to improve the accuracy and quality of the data because the data set is
smaller.
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So, in order to focus more on what we as a school can and are willing to do to improve our air quality
than let’s focus our sample to just faculty and
students. Now does anybody want to take a
guess at how many students and faculty we
have? (Allow students to keep guessing… just for fun!)
• 2, 000 • 2,500 • 1,998 • 4,000
We have approximately 2,000 students and faculty
here are -------------- school.
Why do you think it’s important to know how many people are in our
targeted sample?
To know how many we need to survey to get a
good representative sample.
So now that you know we have ~2,000 in our
targeted sample… how many people do you think
we need to survey?
• 100 • 200 • 250 • 3 • 8
How do you think we
could find out how many we needed exactly?
Some formula
Yes, there is a formula from which you can derive
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the exact number but I have this chart for you all
to look at… Give students chart.
Allow students some time
to look over the chart.
Tell students: The number of surveyed
people needed in order to get a representative
sample is determined by keeping the total number in the target population and confidence interval (which will be discussed
shortly) in mind.
This chart comes from http://www.surveysystem.
com/sscalc.htm the Survey Size Calculator...
(*If there is enough time, perhaps allow students
some time to explore the Survey Size Calculators
with different sample sizes
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and confidence intervals)
Look at the table to determine how many people we need to
survey… So, how many people do
we need to survey to get a representative sample?
• The chart says 696, 323, or 92.
Wow, those are a lot of
numbers and those are VERY different numbers. Which one do you think we are supposed to use?
• 92
Why? Because it’s the smallest number!
Well what makes those numbers different, why do you think there are three different numbers on the chart?
There’s something about “95% confidence interval” and then there is a ±3%,
±5%, and ±10%.
Hmmm… okay let’s break it down. What do you think “95% confidence interval
means?”
• That you 95% confident about something.
95% confident about what?
• You’re results?
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So you’re 95% confident about your results… is
that a good thing?
Yes, it’s pretty close to 100%
Ok, so what do you suppose ±3%, ±5%, and
±10% means?
(Means that you can be 95% confident plus or
minus 3, 5, or ten percent depending upon your
sample size.)
• Maybe, that you’re 95% confident plus or minus 3, 5, or 10%.
• I don’t know
How do we know our confidence interval? What can WE do to increase or decrease our confidence
interval?
• I don’t know • We can decide how
confident we want our results to be and then based on the chart find out exactly how many people must be interviewed.
Which “confidence interval” do you think is the best? Ensures the results are as close to accurate as possible?
±10%
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Why? Because 10 is the biggest number out of 3, 5, and 10%.
Okay, so lets think about what that means…
Write on Board…
95% Confidence plus or minus 10%.
That’s 95%+10%= 105%
And 95% -10%=85%
What does that mean?
That our confidence lies somewhere between 85%
and 105%....
Do you really think we can be 105% confident in our results?
• Yes • No
What about 100% confident? Can we ever be 100% confident in our
results?
• Yes • No
Why do you say no?
Because you just can’t. It’s just not possible; you’d have to survey
everybody in your target sample.
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So how many people do you think we have to interview to be 95% confident at ±10%
interval?
92, according to the chart.
So what is the most important part of the
confidence interval is it the high %? The low % or the range of percentages?
The range of percentages
Why would the range of percentages or the range of the confidence interval be the most important?
Because we want to be as accurate as possible in
testing of our predictions.
So do we still think that ±10% is the most
accurate “confidence interval”?
• No, the best would be ±3%
Why? Because then we’d have a confidence interval of
92%-98% which is smaller confidence interval of 6%
which is better than a difference of 20%
Tell students:
In order to assess what act is more likely to be
What confidence interval will 100 surveys per group
• ±10%
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implemented and thus can realistically improve our
schools air quality.
put us at?
So, you’re job is to get 25 people to take your survey so that as a group you will have 100 survey results, so that we can have a
95% confidence with 10% interval.
Say:
The data that we will get from our survey will be
composed of the number of times a certain option was chosen. In other
words… we will know (in numbers) which option
was chosen most, which one was next, and which option was least chosen.
What are some ways that we can analyze this raw
data? With only that information?
• We can look at the numbers, which one was chosen most, least, and in-between.
• We can look at the averages and compare those.
• I don’t know
What is another word for the average?
• The mean
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How do we calculate the mean or the average of
each option?
• You add the number of times a particular option was chosen and divide that number by the total number of surveys answered. (Do that for all 3 options.)
Good, are there any other ways to analyze the data
by just knowing the number of times that option was chosen?
• Looking at the mode.
Ohhhh, what is the mode? Or how do we find the
mode?
The mode is the particular option that was chosen the MOST of all. So it’s
the response that appears the most
What do you think the
mode tells us about the data?
The option that was chosen most!
Is there anything else we can look at?
• The Median?
What is the median of a data set?
• It’s the middle number
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The middle number? What does that mean?
We don’t have numbers we have options.
The option that was chosen in the middle
I think I know what you’re saying… so if we
surveyed say… 200 people we would look at
the 100th person we looked at?
Yes?
Class, what do we think? The median wouldn’t necessarily work with our
data set Why not? Because our data doesn’t
consist of numbers so the middle person surveyed
wouldn’t tell us much about the overall dataset.
Tell students:
Write about 2 paragraphs describing what you
hypothesis your results will conclude and why.
ELABORATIONELABORATIONELABORATIONELABORATION TUESDAYTUESDAYTUESDAYTUESDAY Time: Time: Time: Time: Entire Class PeriodEntire Class PeriodEntire Class PeriodEntire Class Period What the Teacher Will DoWhat the Teacher Will DoWhat the Teacher Will DoWhat the Teacher Will Do ProbinProbinProbinProbing Questionsg Questionsg Questionsg Questions Student ResponsesStudent ResponsesStudent ResponsesStudent Responses
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Potential MisconceptionsPotential MisconceptionsPotential MisconceptionsPotential Misconceptions
Conduct the survey… (walk around school ask faculty and students which of the three choices they would mostly likely commit to in order to improve the air quality in the school) Record raw data in a chart & Bar Graph. For analysis on Wednesday Write a paragraph describing what they think they found in their results and how that compares to their original hypothesis.
EVALUATIONEVALUATIONEVALUATIONEVALUATION What the Teacher Will DoWhat the Teacher Will DoWhat the Teacher Will DoWhat the Teacher Will Do Probing QuestionsProbing QuestionsProbing QuestionsProbing Questions Student ResponsesStudent ResponsesStudent ResponsesStudent Responses
PoPoPoPotential Misconceptionstential Misconceptionstential Misconceptionstential Misconceptions Evaluation of “exit slip”
Measures of Central Tendency worksheet, before moving on to conducting survey.
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Evaluation of raw data
and graph. Chart: Chart: Chart: Chart:
This chart comes from http://www.surveysystem.com/sscalc.htm the Survey Size Calculator...