Scientific Method Variables

A scientist investigates the effect of carbon dioxide on plant height. The scientist grows plants in several closed containers. All the plants receive the same amounts of water and light, but the air in each container has a different amount of carbon dioxide. What is the independent variable in this experiment?

• the amount of carbon dioxide in each container

• the number of plants in each container

• the amount of water provided to the plants

• the height of each plant after a period of time

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Researchers are developing a new fertilizer designed to improve the growth of endangered Hawaiian plants. The fertilizer was applied to one hundred plants in a greenhouse. The temperature, humidity and amount of water were kept constant. Which is best for the researchers to do next?

• A compare plants that received fertilizer plants that received none

• B begin selling the fertilizer to gardeners living in hot, dry climates

• C change the conditions in the greenhouse and retest the fertilizer

• D test the fertilizer on plants that are adapted to cooler climates

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

NGSS.MS-LS2-4

The “Normal” group in an experiment. You can COMPARE your results to this one (nothing happened to it).

Example: If you are testing the effect of the amount of water on plant growth, this group of plants receives the recommended amount of water.

• Constant

• Variable

• Control Group

• Experimental Group

Which of the following is NOT a characteristic of a hypothesis?

• An idea that is given as an “If...then...statement”

• An idea that can be proven or disproven

• An idea that can never be proven

• A testable idea that leads to a scientific investigation

Tags

NGSS.MS-LS2-4

Why do we want to test one variable at a time?

• Because it is hard to setup a data table with more

• To know what is causing the changes

• It is what has always been done

• No one really knows

Tags

NGSS.MS-PS2-2

Mr. S normally uses praise as a reward to train his dog. He wants to know the best way to train his dog, so he sets up an experiment to find out if there is a better way to get his dog to respond to commands. What is his independent variable?

• Type of reward

• Praise

• Type of dog

• Amount of time the dog follows commands

Tags

NGSS.MS-ETS1-2

Squidward found new reeds to tryout for his clarinet.  He used an APPLAUSOMETER to measure applause after playing  Under the Sea with each reed.  The results were put in the table.
What was the independent variable?

• The Song

• The Reed

• The Applause

Suzan usually walks to school. She wants to see if running to school will help her do better on quizzes in first period. (What is her Independent Variable?)

• How far she walks

• Running to school

• Walking to school

• How well she does on quizzes

This variable in an experiment is the one being changed by the scientist. 

• dependent variable

• independent variable

• data

• control group

In a controlled experiment, the variable that is changed to test the hypothesis is called the –

• Controlled Variable

• Responsive Variable

• Dependent Variable

• Independent Variable

Tags

NGSS.MS-PS2-2