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SCIENTIFIC MEASUREMENTSCIENTIFIC MEASUREMENT

Science 10ACSC

Data Recording Skills

On TargetOn Target

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ACCURACY and ReliabilityACCURACY and Reliability

On TargetOn Target

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ACCURACY and ReliabilityACCURACY and Reliability

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Sustainable Development Overview

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OVERVIEW: Data Recording SkillsOVERVIEW: Data Recording Skills

A- ACCURACY AND RELIABILITYA- ACCURACY AND RELIABILITY B- Recording Measured NumbersB- Recording Measured Numbers C- Reading Measured NumbersC- Reading Measured Numbers D- How Much Data is EnoughD- How Much Data is Enough E- ExperimentingE- ExperimentingACSC Skill Outcomes: ACSC Skill Outcomes: 214-5, 214-8, 214-10, 215-2214-5, 214-8, 214-10, 215-2

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A-Accuracy and ReliabilityA-Accuracy and Reliability This animation may This animation may

give the impression of give the impression of 100% accuracy and 100% accuracy and 100% reliability 100% reliability However real data is However real data is not like that. not like that.

Real data always has Real data always has experimental error. experimental error. (uncertainty NOT (uncertainty NOT mistake) mistake)

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B-Recording Measured NumbersB-Recording Measured Numbers“Significant Figures”“Significant Figures” Features & BenefitsFeatures & Benefits skip to end skip to end -->

FeaturesFeatures, “Significant Figures” include the following:, “Significant Figures” include the following:

All accurately known digits are recordedAll accurately known digits are recorded

One digit with opinion is recorded, (estimate One digit with opinion is recorded, (estimate

tenths in the smallest graduation)tenths in the smallest graduation)

Counted and defined numbers have infinite Counted and defined numbers have infinite

significance. significance.

BenefitsBenefits

Accurately recorded digits give clues to the Accurately recorded digits give clues to the

reliability and reproducibility of the data.reliability and reproducibility of the data.

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C-Reading Measured NumbersC-Reading Measured Numbers“Significant Figures”“Significant Figures” Features & BenefitsFeatures & Benefits skip to end skip to end -->

FeaturesFeatures, “Significant Figures” examples:, “Significant Figures” examples:

All nonzero digits are significantAll nonzero digits are significant

Counted and defined numbers have infinite significance.Counted and defined numbers have infinite significance.

Zeros, which ones are significant and which are just space Zeros, which ones are significant and which are just space

holders?holders?

BenefitsBenefits

Accurately read digits preserve the validity and Accurately read digits preserve the validity and

reproducibility of the data.reproducibility of the data.

Document

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D-Data Collection: D-Data Collection: How much data is enough?How much data is enough? Skip to end-> Skip to end->

Test (Test (Practice, Practice, until the trials are “fair tests.” (trials must until the trials are “fair tests.” (trials must be comparable and consistent)be comparable and consistent)

Test Test (Experimental (Experimental Bias: method/experimenter introduced trends)) Practice the method until method biases or the Practice the method until method biases or the lack of them become obvious.lack of them become obvious.

Test (Test (Trends) Trends) collect data until trends or lack of them collect data until trends or lack of them become obvious.become obvious.

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E- Experimenting E- Experimenting skip to end->skip to end->

There are several practical things which can There are several practical things which can be done to control variables for a fair test.be done to control variables for a fair test.

Do all trials, to be compared, on the same day.Do all trials, to be compared, on the same day. Manipulate or change only one variable. Manipulate or change only one variable. Practice until you can collect reliable data that is, Practice until you can collect reliable data that is,

the tests are fair.the tests are fair. Use the same method being careful to do Use the same method being careful to do

everything exactly the same to collect the data.everything exactly the same to collect the data.

Document Scientific attitudes are important. They Scientific attitudes are important. They

dictate accuracy clarity and soundness of dictate accuracy clarity and soundness of scientific arguments.scientific arguments.

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E-Data Graphing:E-Data Graphing: What does the shape and graph distribution tell you? What does the shape and graph distribution tell you?

Skip to end->Skip to end->

Plot the test data on the graph to see how well the Plot the test data on the graph to see how well the actual trials fit in the corridor of success .actual trials fit in the corridor of success .

Look for trends or the lack of them suggested by the Look for trends or the lack of them suggested by the shape of the graph.shape of the graph.

If you had to hit a target accurately are some angles If you had to hit a target accurately are some angles better to shoot from? How is this indicated by the better to shoot from? How is this indicated by the corridor of success? corridor of success?

In this case is more reliable likely to be more In this case is more reliable likely to be more accurate?accurate?

Graphing for CLARITYGraphing for CLARITY

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Internet AvailabilityInternet Availability

Science 10 ACSC development site http://Science 10 ACSC development site http://scifairscifair..ednetednet..nsns.ca/science10.ca/science10

Central Kings Science 10Central Kings Science 10 <<http://scifair.ednet.ns.ca/CKCLS/index~PHS.html>http://scifair.ednet.ns.ca/CKCLS/index~PHS.html>

Review Buttons Review Buttons (Accuracy and Reliability)(Accuracy and Reliability)

Recording Measured Numbers Recording Measured Numbers (Significant figures)(Significant figures)

Reading Measured numbersReading Measured numbers

Data Collection (How much is enough?)Data Collection (How much is enough?)

ExperimentingExperimenting

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Prediction: Corridor of SuccessPrediction: Corridor of Success The experimental max./min. air times were added to the spreadsheet.The experimental max./min. air times were added to the spreadsheet.

• Then the graph will update to show the expected minimum and Then the graph will update to show the expected minimum and maximum range of the projectile. maximum range of the projectile.

time: t(air)av 6.2 V (mid) 30.38 Shot Elevation 1.5

_ t(air)max 6.8 V (max) 33.32 _ t(air)min 5.5 V (min) 26.95

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Launch Angle Range (max.) Range (min.)

0 18.44 14.91

5 38.04 31.23

10 56.90 43.50

15 74.45 54.86

20 90.14 64.96

25 103.49 73.48

30 114.08 80.15

35 121.56 84.74

40 125.69 87.11

45 126.32 87.15

50 123.42 84.84

55 117.03 80.22

60 107.33 73.40

65 94.57 64.56

70 79.13 53.94

75 61.42 41.83

80 41.95 28.55

85 21.28 14.48

90 0.00 0.00

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0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90Launch Angle

Range

Range (max.)

Range (min.)

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