Lesson 1

Identifying Independent and Dependent Variables

VARIABLES

something that is able to be changed or adapted

Independent Variables

what you change in a scientific experiment

Dependent variable

what changes because of the independent variable, what you are trying to figure out or understand

often the result of the experiment

Example

• Are students who are involved in school sports more likely to have a higher grade point average?

• The dependent variable would be the grade point average of the students who participated in the experiment.

• The dependent variable should be measureable or observeable.

Try to identify the independent and dependent variables in the following examples.

Example

• Are students who are involved in school sports more likely to have a higher grade point average?

• The independent variable would be whether or not students are involved in school sports. Because that is what we can change.

Multiple Choice

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

• Amount of water given to the plants

• Type of soil used

• Amount of sunlight received

• Height of the plants

Multiple Choice

What is the independent variable?

• how much salt put in the water

• whether the object floats or sinks

Multiple Choice

What is the independent variable?

• how far the ball rolls

• the incline or height of the board

Multiple Choice

What is the independent variable?

• the temperature

• how the ball bounces

Multiple Choice

What is the independent variable?

• putting soap on a coin

• how much water fits on the coin

Multiple Choice

What is the independent variable?

• how fast the salt melts

• the amount of salt put on the ice cube

Multiple Choice

What is the dependent variable?

• music played for the plant

• how the plant grows

Multiple Choice

What is the dependent variable?

• the texture of the cookie

• the amount of baking powder added to the recipe

Multiple Choice

What is the dependent variable?

• how much mold grows

• the amount of light

Multiple Choice

What is the dependent variable?

• how long it takes the clothes to dry

• the temperature

Multiple Choice

What is the dependent variable?

• adding water

• whether the balloon burst

Multiple Choice

Which of the following is a dependent variable in an experiment measuring the effect of fertilizer on plant height?

• Type of fertilizer used

• Amount of fertilizer used

• Height of the plants

• Type of plants used

Multiple Choice

In an experiment, if you are testing how different temperatures affect the rate of a chemical reaction, what is the dependent variable?

• Temperature

• Rate of the chemical reaction

• Type of chemical used

• Volume of the chemical

Multiple Choice

Which of the following best describes the relationship between an independent variable and a dependent variable?

• The independent variable is changed to observe its effect on the dependent variable.

• The dependent variable is changed to observe its effect on the independent variable.

• Both variables are changed simultaneously.

• Neither variable is changed.

Multiple Choice

In an experiment to determine the effect of different amounts of sleep on test scores, what would be the independent variable?

• Test scores

• Amount of sleep

• Type of test

• Time of day the test is taken

Multiple Choice

You are designing an experiment to test the effect of different types of music on concentration levels. What would be a suitable dependent variable?

• Type of music

• Volume of music

• Concentration levels

• Duration of the experiment

Multiple Choice

In an experiment to test the effect of different fertilizers on plant growth, you measure the height of the plants every week. What is the dependent variable?

• Type of fertilizer

• Height of the plants

• Amount of water

• Type of plants

Multiple Choice

You are asked to design an experiment to test how the amount of exercise affects heart rate. Which of the following would be the independent variable?

• Heart rate

• Amount of exercise

• Type of exercise

• Age of participants

Multiple Choice

In an experiment to determine the effect of different amounts of water on plant growth, what is the dependent variable?

• Amount of water

• Type of plant

• Growth of the plant

• Type of soil

Multiple Choice

You are analyzing data from an experiment where different amounts of light were given to plants to see how it affects their growth. What is the independent variable?

• Amount of light

• Growth of the plants

• Type of plant

• Type of soil

Multiple Choice

Design an experiment to test the effect of different study techniques on test scores. What would be the independent variable?

• Test scores

• Study techniques

• Duration of study

• Subject of the test

Multiple Choice

In an experiment to test the effect of temperature on the solubility of a substance, what would be the dependent variable?

• Temperature

• Solubility of the substance

• Type of substance

• Volume of solvent

Multiple Choice

You are asked to analyze data from an experiment where different amounts of fertilizer were used to see their effect on plant growth. What is the dependent variable?

• Amount of fertilizer

• Type of plant

• Growth of the plant

• Type of soil

Multiple Choice

In an experiment to test the effect of different types of soil on plant growth, what would be the independent variable?

• Type of soil

• Amount of water

• Growth of the plant

• Type of plant

Multiple Choice

You are designing an experiment to test how different amounts of sleep affect memory retention. What would be a suitable dependent variable?

• Amount of sleep

• Memory retention

• Type of memory test

• Age of participants

Multiple Choice

What is the independent variable in the question below?

Will hair have more shine if conditioneer is used before or after shampooing?

• Shininess of hair

• When the hair is conditioned

Multiple Choice

What is the dependent variable in the question below?

Are children who learn to read before kindergarten more likely to attend college?

• when students learn to read

• likeliness to attend college

• what students read

Multiple Choice

What is the dependent variable in the question below?

Are fisherment who use live bate more likely to catch a fish than fisherman who use artificial (fake) bait?

• likeliness of catching fish

• what bait is used

Multiple Choice

What is the independent variable in the question below?

When students bring a packed lunch to school do they consume fewer calories?

• Whether or not students bring a packed lunch or eat a school lunch

• how many calories students consume

Multiple Choice

What is the independint variable in the question below?

Do movie goers eat more popcorn during comedies or dramas?

• the amount of popcorn eaten during the movie

• which movie is seen