Experimental Variables and Control Groups

The video tutorial introduces the concept of variables in scientific experiments, explaining independent, dependent, and constant variables. It emphasizes the importance of conducting multiple trials to ensure accuracy and minimize human error. Three scenarios are presented: Janice's toy shop experiment with caffeine, Bill's cookie experiment with chocolate chips, and Suzy Q's plant light experiment. Each scenario illustrates how to identify and control variables. The video concludes with instructions for students to complete an assignment on Ed Moto.

What is an independent variable in an experiment?

• A variable that is kept constant

• A variable that is not measured

• A variable that is changed by the experimenter

• A variable that responds to changes

What does a dependent variable represent in an experiment?

• A variable that is not measured

• A variable that is manipulated

• A variable that responds to changes in the independent variable

• A variable that remains unchanged

Why is it important to conduct multiple trials in an experiment?

• To confuse the participants

• To make the experiment more complex

• To ensure accuracy and account for human error

• To save time

Why is a control group important in an experiment?

• To confuse the results

• To make the experiment more interesting

• To provide a basis for comparison

• To increase the number of variables

In Janice's toy shop experiment, what was the independent variable?

• The type of toys

• The time given to construct toys

• The number of toys constructed

• The caffeine given to Group A

What was the control group in Janice's experiment?

• Neither group

• Both groups

• Group B

• Group A

In Bill's cookie experiment, what was the dependent variable?

• The oven temperature

• The texture of the cookies

• The baking time

• The number of cookies baked

What should be kept constant in Bill's cookie experiment?

• The recipe and baking conditions

• The type of chocolate used

• The amount of chocolate chips

• The number of cookies

In Suzy Q's plant light experiment, what was the independent variable?

• The color of light

• The amount of water given

• The type of soil used

• The species of plants

What was the purpose of the plant placed in the closet in Suzy Q's experiment?

• To grow faster

• To receive the most light

• To act as a control group

• To test a new soil type