SAB Workshop

1
SAB Workshop 2

• Experimentation and Results

2
Introduction to the Scientific Method

• Stating the problem
• Making a hypothesis (Ifthen)
• Gathering data
• Analyzing data
• Drawing conclusions

3
Stating the Problem Sample Project

• We want to find whether a persons hand size has
  any relationship to the number of marbles he/she
  can pick up

4
Making a Hypothesis Sample Project

• If the hand size of a person increases then the
  number of marbles that person can pick up will
  increase.

5
Gathering Data - Variables

• Every experiment has three types of variables
  independent, dependent, and controlled
• Independent variable the ONE thing you will
  change
• Dependent variable what you will measure
• Controlled variable what is kept constant

6
Independent, Dependent, and Controlled Variables
for the Sample Project

• Independent? Hand size (inches from wrist to top
  of middle finger)
• Dependent? Number of marbles that person can pick
  up
• Controlled? Size of the marbles, for each person
  the hand used must be the same (right hand, left
  hand), time used to pick up marbles

7
Gathering Data - Do the Experiments

• Do many trials
• Make sure your experiment can be reproduced
• Write down the steps of your experiment
• Record all data
• Make sure your results can be compared to some
  standard

8
Do the Experiments Sample Project

• How many trials per person? 5
• Procedure?
• 1. Set a limit for how long each person has to
  pick up marbles.
• 2. Measure the hand size of the person using a
  ruler.
• 3. Put the marbles in a certain-sized container
  (small basket in this case)
• 4. Have a person pick up marbles.
• 5. Count the number of marbles.
• 6. Record the number of marbles.
• 7. Put the marbles back.
• 8. Repeat this for the number of trials needed.
• 9. Repeat for all the people.

9
Analyzing Data

• Do statistics if necessary
• Graphs!

10
Analyzing Data Sample Project

• Each person find the AVERAGE (MEAN) of his/her
  data
• Make a LINE GRAPH of independent variable
  (x-axis) vs. dependent variable (y-axis)

of Marbles
Hand size
11
Graphs Sample Project
12
Analyzing Data Interpret Results

• What do your data say?

13
Interpret Results Sample Project

• Is there a relationship? If so, what kind? Not
  very strong. As the hand size increases, the
  number marbles picked up may or may not increase.
  
• It is also possible to make a mathematical model

14
Draw Conclusions

• Is your hypothesis correct? (DO NOT change your
  hypothesis or your data to make the hypothesis
  correct)
• What were some sources of error?
• What could you do differently next time to make
  your experiment better?

15
Draw Conclusions Sample Project

• Is the hypothesis correct? No.
• Sources of error? Container, texture of the hand,
  tiredness of hand
• Improvements? Bowl should be round and larger
  with no holes have everyone wash hands before
  take a little more time between each trial to let
  people relax make the time limit more strict but
  reasonable use centimeters instead of inches.