Variables in Science

What is an independent variable?

• A variable that stays constant throughout the experiment

• A variable that is not important in the experiment

• A variable that is only used in qualitative research

• A variable that is manipulated or changed by the experimenter

In an experiment to test the effect of sunlight on plant growth, what is the independent variable?

• Soil type

• Temperature

• Water

• Sunlight

What is a dependent variable?

• The variable that is manipulated in a scientific experiment.

• The variable that remains constant in a scientific experiment.

• The variable that is not important in a scientific experiment.

• The variable being tested and measured in a scientific experiment.

In an experiment to test the effect of temperature on ice melting, what is the dependent variable?

• Rate of ice melting

• Color of the ice

• Type of container used

• Amount of water added

Tags

NGSS.MS-PS1-4

What is a controlled variable?

• A factor that changes in an experiment

• A factor that is kept constant in an experiment

• A variable that is only used in social science experiments

• A variable that is not important in an experiment

In an experiment to test the effect of different fertilizers on plant growth, what are some examples of controlled variables?

• Type of plant, amount of water and sunlight, temperature, size of pots, type of soil

• Time of day the fertilizer is applied

• Brand of the fertilizer

• Color of the fertilizer

Tags

NGSS.MS-LS1-5

Identify the independent variable in the following scenario: A study to determine the effect of exercise on heart rate.

• Type of heart rate

• Level of exercise

• Effect on heart rate

• Duration of the study

Identify the dependent variable in the following scenario: A study to determine the effect of caffeine on reaction time.

• Time of day the study was conducted

• Type of reaction tested

• Reaction time

• Amount of caffeine consumed

Find the Independent Variable: You experiment to see if a bouncy ball or a tennis ball bounces higher.

• Type of ball

• Same drop height

• Height of bounce

• Same surface

Students of different ages were given the same puzzle to assemble. The puzzle assembly time was measured. What is the independent variable?

• age of students

• time to complete the puzzle

• number of pieces in the puzzle

• same testing environment