Dependent and Independent Variables

IDENTIFY THE DEPENDENT VARIABLE FOR THE HYPOTHESIS:

Fertilizer will increase the rate of grass growth

Rate of grass growth

IDENTIFY THE DEPENDENT VARIABLE FOR THE HYPOTHESIS:

Drinking extra water before a test will improve test scores

test scores

IDENTIFY THE DEPENDENT VARIABLE FOR THE HYPOTHESIS:

Hair will grow faster if a special cream is applied

rate of hair growth

IDENTIFY THE DEPENDENT VARIABLE FOR THE HYPOTHESIS:

A steel alloy will be stronger if the amount of chromium is increased

strength of the steel alloy

IDENTIFY THE DEPENDENT VARIABLE FOR THE HYPOTHESIS:

Wood will burn slower if a special retardant is applied.

rate at which the wood burns

IDENTIFY THE DEPENDENT VARIABLE FOR THE HYPOTHESIS:

If fluoride is added to the city drinking water, the number of cavities will be reduced.

number of cavities

IDENTIFY THE DEPENDENT VARIABLE FOR THE HYPOTHESIS:

Applying a special coating to solar cells will make them last longer.

how long the solar cells last

IDENTIFY THE DEPENDENT VARIABLE FOR THE HYPOTHESIS:

If "Factory X" stops polluting Big Creek, then the trout population will grow.

population size of the trout (I would accept "rate of population growth")

IDENTIFY THE DEPENDENT VARIABLE FOR THE HYPOTHESIS:

There will be a decrease in the number of cases of Malaria in Village A if they are provided with, and use, mosquito netting.

number of cases of malaria

IDENTIFY THE INDEPENDENT VARIABLE FOR THE HYPOTHESIS:

Fertilizer will increase the rate of grass growth

Fertilizer or no fertilizer

IDENTIFY THE INDEPENDENT VARIABLE FOR THE HYPOTHESIS:

Drinking extra water before a test will improve test scores

Extra water or no extra water

IDENTIFY THE INDEPENDENT VARIABLE FOR THE HYPOTHESIS:

Hair will grow faster if a special cream is applied

Special cream or no special cream

IDENTIFY THE INDEPENDENT VARIABLE FOR THE HYPOTHESIS:

A steel alloy will be stronger if the amount of chromium is increased

The amount of chromium increased or not increased

IDENTIFY THE INDEPENDENT VARIABLE FOR THE HYPOTHESIS:

Wood will burn slower if a special retardant is applied.

Retardant or no retardant

IDENTIFY THE INDEPENDENT VARIABLE FOR THE HYPOTHESIS:

If fluoride is added to the city drinking water, the number of cavities will be reduced.

Fluoride or no fluoride

IDENTIFY THE INDEPENDENT VARIABLE FOR THE HYPOTHESIS:

Applying a special coating to solar cells will make them last longer.

Special coating or no special coating

IDENTIFY THE INDEPENDENT VARIABLE FOR THE HYPOTHESIS:

If "Factory X" stops polluting Big Creek, then the trout population will grow.

Polluting or not polluting Big Creek

IDENTIFY THE INDEPENDENT VARIABLE FOR THE HYPOTHESIS:

There will be a decrease in the rate of Malaria in Village A if they are provided with, and use, mosquito netting.

Use, or no use, of mosquito netting

Plants that get regular watering grow taller.

Independent variable : water
Dependent variable : plants growth.

At-risk children attending head start get better grades in reading in second grade.

Independent variable : head start
Dependent variable : grades

People who smoke cigarettes have a higher incidence of lung cancer.

Independent variable : smoking
Dependent variable : lung cancer

Puppies that are given vitamins gain more weight.

Independent variable : vitamins
Dependent variables : weight

Hot water dissolves more sugar.

Independent variable : hot water
Dependent variable : dissolves more sugar

Hikers wearing lighter weight boots can hike more miles than hikers wearing heavier boots.

Independent variable : boots
Dependent variable : miles hiked

Sunflowers getting more water grow over six feet tall.

Independent variable : water
Dependent variable : height of sunflower

Children taking asthma medication have fewer asthma attacks.

Independent variable : medicine
Dependent variable : asthma attacks

If knee replacement patients participate in immediate physical therapy, they can climb stairs three days after surgery.

Independent variable : patients attend PT
Dependent variable : how fast recovery

People exposed to asbestos have a greater incidence of mesothelioma.

Independent variable : asbestos exposure
Dependent variable : mesothelioma

Athletes receiving at least 8 hours of sleep the night before the race will run faster.

Independent variable : 8 hours of sleep
Dependent variable : how fast they run

If a person takes a daily multivitamin, they can extend their life expectancy.

Independent variable- taking vitamin
Dependent- longer life span

Time

What is the independent variable?

The drug

A scientist studies the impact of a drug on cancer.
What is the independent variable?

the number of lifeguards scheduled to work

The number of lifeguards scheduled to work at the community pool on a given day varies depending on how many swimmers are expected to visit the pool on that day
What is the dependent variable?

the number of tickets the friends have won

Minh and her friends are at an arcade and are redeeming their tickets for prizes. The number of tickets they have won determines how many prizes they can get.
What is the independent variable?

the amount of money Warren's quartet earns

In order to earn extra money on the weekends, Warren's string quartet performs at wedding receptions. The longer the reception, the more money they earn.
What is the dependent variable?

the salad's weight

Gabrielle makes a salad at a salad bar. The cost of the salad is calculated according to its weight.
What is the independent variable?

the team's score

In hockey, a team's score depends on how many goals the team has score.
What is the dependent variable?

the number of hours Adon spends reading every day

Over summer vacation, Adon has to read a novel for English class. He has decided to spend the same amount of time reading every day. The number of days it will take him to finish the book depends on how many hours he spends reading every day.
What is the independent variable?

variable

an element, feature, or factor that can be changed

controlled variables (aka constants)

the variables that stay the same for entire experiment

independent (manipulated) variable

a variable that is changed by the experiment, there is only one

dependent (responding) variable

the variable that is measured or observed

Does the age of compost (rotten plant material) affect how many tomatoes a tomato plant produces? What is the independent variable?

age of the compost

Does the age of compost (rotten plant material) affect how many tomatoes a tomato plant produces? What is the dependent variable?

the number of tomatoes

What is the effect of loud music on the ability to memorize a list of random words? What is an appropriate control group?

memorizing list of random words without music

Does the age of compost (rotten plant material) affect how many tomatoes a tomato plant produces? What is an appropriate control group?

tomatoes with no compost

What is the effect of loud music on the ability to memorize a list of random words? What is the independent variable?

loud music

What is the effect of loud music on the ability to memorize a list of random words? What is the dependent variable?

the ability to memorize a list of random words

What is the effect of loud music on the ability to memorize a list of random words? What are at least two factors that should be kept the same?

same environment, same words, given the same amount of time, same time of day

Does the age of compost (rotten plant material) affect how many tomatoes a tomato plant produces? What are at least two factors that should be kept the same?

type of tomato plants, amount of water, amount of sun, same environment

Will the boiling point of water change if salt is added? What is the dependent variable?

boiling point of water

Will the boiling point of water change if salt is added? What is the independent variable?

salt

Will the boiling point of water change if salt is added? What is an appropriate control group?

water with no salt

Will the boiling point of water change if salt is added? What are some variables that should be help constant?

amount of water, the same place, same type of water

In an experiment to test that a vitamin could extend a person's life-expectancy, then: lifespan would be the

dependent variable

In an experiment to test that a vitamin could extend a person's life-expectancy, then: the amount of vitamin that is given to the subjects within the experiment. This is controlled by the experimenting scientist.

independent variable

In an experiment to test how the amount of sunlight affects the growth of radishes. the amount of sunlight each plant receives.

independent variable

In an experiment to test how the amount of sunlight affects the growth of radishes. the growth fo the radishes is the

dependent variable

In an experiment to test the effect an insecticide has on keeping earwigs out of the house, the type of insecticide used is the

independent variable

In an experiment to test the effect an insecticide has on keeping earwigs out of the house, a number of earwigs out of the house

dependent variable

In an experiment to test the effect of sleep deprivation on student test scores, the amount of sleep a student would get nightly is the

independent variable

In an experiment to test the effect of sleep deprivation on student test scores, effect on the student's test scores would be the

dependent variable