Experimental Design

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Experimental Design

• Starter 8.15.07

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Identify the independent variable and dependent
variablea. Michael put 100 red seeds, 100 brown
seeds, and 100 yellow seeds in his bird feeder.
He counted the number of seeds of each color that
remained after 2 days

• Starter 8.15.07
• Independent Variable
• Dependent Variable

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2. Identify the independent variable, dependent
variable, and constants a. Elizabeth tested
how high 5 different brands of new tennis balls
would bounce when dropped from a height of 2
meters. She dropped the balls that they hit the
same floor tile each time.

1. Independent Variable
2. Dependent Variable
3. Constants

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Practice Problem 1

• Determine if the hypothesis is supported by the
  data. Explain why?
• Katherine thought that people would be able to
  taste small amounts of sugar more easily than
  vinegar or salt. She found that people could
  detect 2 ml of salt in a liter of water. However,
  they needed only 1.5 ml of sugar per liter of
  water and .5 ml of vinegar to taste the
  substance.
• 1. Answer

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Practice Problem 2
Amount of Salt in Water Height of Top of Eggs (cm) Trials Height of Top of Eggs (cm) Trials Height of Top of Eggs (cm) Trials
Amount of Salt in Water 1 2 3
0 4 4 4
10 5 6 5
20 8 8 8

1. What conclusion might you draw from the data
   presented in the chart above?
2. Can you find any trends or patterns in the data?

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Practice Problem 3
Amount of Salt in Water Height of Top of Eggs (cm) Trials Height of Top of Eggs (cm) Trials Height of Top of Eggs (cm) Trials
Amount of Salt in Water 1 2 3
0 4 4 4
10 5 6 5
20 8 8 8

1. Find the average height of top of eggs for each
   level.
2. Why are repeated trials important to an
   experiment?