Module 3 (pt 1)

Question 1

1a. Define: Experimental variable

Answer 1

An aspect of an experiment that changes during the course of the experiment

Question 2

1b. Define: Control (of an experiment)

Answer 2

The variable or part of the experiment to which all others will be compared

Question 3

1c. Define: Blind experiments

Answer 3

Experiments in which the participants do not know whether or not they are a part of the control group

Question 4

1d. Define: Double-blind experiments

Answer 4

Experiments in which neither the participants not the people analyzing the results know who is in the control group

Question 5

2. When is an experimental variable good and when should it be reduced or eliminated?

Answer 5

An experimental variable is good when you are using it to learn something from the experiment. An experimental variable should be reduced or eliminated when it affects the results of the experiment but you do not learn anything from it.

Question 6

3. (Read story on page 80) What is the control for this experiment?

Answer 6

the shirt that is being washed with no laundry detergent at all

Question 7

4. (Read story on page 80) What is the experimental variable that will be used to learn something from the experiment?

Answer 7

the type of detergent used

Question 8

5. (Read story on page 80) What are the experimental variables that need to be reduced or eliminated?

Answer 8

the washers are different, the water can be at different temperatures, the shirts are different and finally, the amount of grass stain will be different in each shirt