How do we know what we know

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					  “How Do You Know
    What I Know?”
Representing Your Data
     Matthew Sender
  Mentor: Dr. Grant Krow
 Teacher: Maria Fitzgerald
 First Step, Proper Data Collection
What data should we collect?
  The data you collect should allow you to
 answer the question you are investigating.
How should we collect our data?
 Proper data collection is methodical, rather
 than haphazard.
       A Record Book Is Essential!
              Plan your experiment before you begin

              This includes:
Record Book
              • What materials you will need
              • Step by step procedural guide
              • Space to record your observations

              Just like your school lab book

              The big difference is that you are designing
              the experiment
 How Do You Investigate a Question?
• Questions are investigated by careful control
  of the experimental conditions such that only
  “the thing” being studied is changing.
• Another essential piece is to have a control
  experiment.
  – A Control experiment is one in which the
    experiment is carried out without including the
    variable.
     What About the Precision and
       Accuracy of Our Data?
• In order to assess the precision of our data we
  need to run each experiment more than once
• Optimally 3-5 times for each experiment

• In order to properly assess the accuracy of our
  data we need to know the “true” value of
  whatever we are measuring.
 How Do We Represent Our Data Now
        That It Is Collected?
Figures and Tables!
- Figures, such as graphs, are very effective at
  showing trends and relationships
- Figures, such as diagrams or pictures, are
  effective at showing visual data, or
  experimental apparatus
- Tables are very effective at showing values for
  comparison.
 An Example: Heating Curve of Water
Time    Temperature                         Heating Curve of Water
                      120
0:00        23

1:25        31
                      100
2:50        42

4:30        53
                      80
5:38        60

6:55        70        60

8:12        80
                      40
9:32        90

11:00       100
                      20
12:42       103

14:41       103        0
                           0:00   2:24   4:48   7:12   9:36   12:00   14:24   16:48   19:12
17:41       103
                Let’s Spice It Up
Question to be studied-
      What is the effect of flame height on the
      heating curve of water?

What do we have to do so that we collect
quality data to answer our question?
Materials   Method   Data
 Materials                  Method                          Data
                            1.   Add 50 mL of water to
 • Stopwatch                     cup
                                                            To Record:
 • Heatable cup with        2.   Light Bunsen burner and    Flame Height,
   volume markings               adjust flame to 4 inches   Trial ,Time,
 • Ruler                    3.   Place cup 5 inches from        Temperature
                                 top of Bunsen burner
 • Bunsen burner
                            4.   Record temperature
 • Gas supply                    every minute until the
 • 1 L of bottled water          temperature is constant,
 • Stand                         then continue to heat
                                 and observe for 3
 • Clamp                         minutes.
 • Thermometer              5.   Repeat 2X, then repeat
                                 3X each adjusting the
                                 flame height to 5 and 6
                                 inches

How many variables in our method can we find? How many are we changing?
                          Fake “Collected” Data
                                           Flame Height 6”                            Flame Height 5”
Flame Height 4”
                                                   Trial 1 Trial 2 Trial 3 Average            Trial 1 Trial 2 Trial 3 Average
        Trial 1 Trial 2 Trial 3 Average
                                           Min     Temp Temp Temp Temp                Min     Temp Temp Temp Temp
Min     Temp Temp Temp Temp
                                               1.1     23       23     23        23       1.1     23       23     23        23
    1.1      23       23     23       23
                                               2.1     42       43     41        42       2.1     36       37     38        37
    2.1      31       30     33       31
                                               3.3     60       61     61        61       3.3     51       53     52        52
    3.3      42       43     41       42
                                               4.2     80       81     81        81       4.2     66       68     67        67
    4.2      53       53     53       53
                                               5.4 100         101 100          100       5.4     82       81     81        81
    5.4      60       61     61       61
                                               6.4 103         103 103          103       6.4     97       96     97        97
    6.4      70       71     71       71
                                               7.3 103         103 103          103       7.3 103         103 103          103
    7.3      80       81     81       81
                                               8.2 103         103 103          103       8.2 103         103 103          103
    8.2      90       89     90       90
                                                                                          9.2 103         103 103          103
    9.2    100      101     100      100
   10.4    103      103     103      103
   11.5    103      103     103      103
   12.3    103      103     103      103




                        Which flame height has the fastest rate of heating?
                             Graphing All of the Data
                                 Affect of Flame Height on Heating Curve
                   120



                   100



                                                                                4" Flame Trial1
                   80
                                                                                4" Flame Trial 2
Temperature (oC)




                                                                                4" Flame Trial 3
                   60                                                           6" Flame Trial 1
                                                                                6" Flame Trial 2
                                                                                6" Flame Trial 3
                   40
                                                                                5" Flame Trial 1
                                                                                5" Flame Trial 2
                                                                                5" Flame Trial 3
                   20



                     0
                         0   2    4        6                8   10    12   14
                                               Time (min)
Graphing Mathematically Treated Data
                                 Affect of Flame Height on Heating Curve
                   120



                   100



                   80
Temperature (oC)




                   60                                                                4" Flame
                                                                                     6" Flame
                                                                                     5" Flame
                   40



                   20



                     0
                         0   2     4         6                8   10       12   14
                                                 Time (min)
Tables Can Be Very Effective As Well

Even graphs can be made more succinct
if you are able to get the
right information out of your data


         Flame Height   Heating Rate
         (inches)       (oC/min)
                 4              9
                 5             14
                 6             18

				
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