Experimental Design

Your teacher has asked you to perform an experiment to see if the shape of objects, alone, affects the motion of objects. Which of the following would be the best experiment to perform?

• Apply the same amount of force to a ball, cylinder, cube, and pyramid, each of the same mass.

• Apply the same amount of force to balls of different mass

• Apply the same amount of force to a ball, cylinder, cube, and pyramid, each of a different mass.

• 
  Apply different amounts of force to the same ball.

In a controlled scientific experiment, a scientist...

• alters the outcome variable (dependent variable) and observes the effects on the test variable (independent variable).

• alters one test variable (independent variable) and observes the effects on other test variables (independent variables).

• alters the test variable (independent variable) and observes the effects on the outcome variable (dependent variable).

• 
  alters one outcome variable (dependent variable) and observes the effects on other outcome variable (dependent variables).

Tags

NGSS.MS-PS2-2

Look at the image of Corey's Science Experiment. What is wrong with the steps of Corey's science experiment?

• The log was going to completely burn; therefore, there wouldn't be any ashes left to measure.

• He didn't measure the weight of the log before it was burned.

• He didn't set a time limit on how long he was going to let the log burn.

• He didn't have a partner there in order to verify the results.

Tags

NGSS.MS-ETS1-1

NGSS.MS-PS1-5

NGSS.MS-PS3-4

You have decided to do an experiment to learn if a certain type of cactus will grow better in a dark closet or a sunny window. To begin your experiment, you place one cactus in a dark closet and one cactus in a sunny window. Over the next month, you record data about the cacti and their appearance every day. At the end of the month, you determine that the cactus in the sun is alive but didn’t grow and that the cactus from the dark closet is alive and grew one centimeter. Can you conclude that a dark closet is better for this type of cacti’s growth?

• No, you need to repeat an experiment multiple times before accepting a conclusion.

• Yes, one cactus can accurately reflect the behavior of all similar cacti.

• Yes, when you are a student your results will be accepted on small-scale studies.

• No, you need to use one cactus in both conditions.

Tags

NGSS.MS-ETS1-1

Juan is interested in finding out whether hummingbirds are attracted to some flowers more than others. In what order should Juan perform the steps of his experiment?

• Write a report on his findings.

• Observe how many times hummingbirds visit each flowers.

• Make a prediction about which flowers hummingbirds are most attracted to.

• Record her observations.

• Create garden of different flowers.

Nick is conducting a controlled experiment to test whether music helps daisies grow faster. Below are the steps to Nick's experiment. Which group is the control group?

• the green room

• the music

• flowerpot 2

• flowerpot 1

Tags

NGSS.MS-LS1-5

When more than one variable in an experiment is changed at a time, the scientist....

• cannot accurately measure both variables at the same time.

• needs to conduct more trials in order to get conclusive results.

• cannot tell which change produced the results.

• made a systematic error that needs to be corrected.

Tags

NGSS.MS-PS2-2

Maggie loves fresh brownies. Her grandma told her if she placed a piece of bread in the storage container with the brownies, the brownies will stay fresh and moist longer. Maggie decides to test this idea. She bakes a batch of brownies. She places 6 brownies in 6 individual plastic containers. Each brownie is the same size and placed in the same location. She adds a piece of bread to three of the bread containers and leaves the other three alone. Each day for 3 weeks she measures the moistness of the brownies and records the results. What is the independent variable?

• moistness of brownies

• the bread

• the containers

• brownies

Answer explanation

Tags

NGSS.MS-LS2-1

Maggie loves fresh brownies. Her grandma told her if she placed a piece of bread in the storage container with the brownies, the brownies will stay fresh and moist longer. Maggie decides to test this idea. She bakes a batch of brownies. She places 6 brownies in 6 individual plastic containers. Each brownie is the same size and placed in the same location. She adds a piece of bread to three of the bread containers and leaves the other three alone. Each day for 3 weeks she measures the moistness of the brownies and records the results. What is the dependent variable?

• The size of the brownies
• The type of container used
• The presence of bread in the container
• The moistness of the brownies

Tags

NGSS.MS-PS1-2

Maggie loves fresh brownies. Her grandma told her if she placed a piece of bread in the storage container with the brownies, the brownies will stay fresh and moist longer. Maggie decides to test this idea. She bakes a batch of brownies. She places 6 brownies in 6 individual plastic containers. Each brownie is the same size and placed in the same location. She adds a piece of bread to three of the bread containers and leaves the other three alone. Each day for 3 weeks she measures the moistness of the brownies and records the results. What is the control group?

• The brownies that were stored with a piece of bread
• The brownies that were stored without a piece of bread
• The size of the brownies
• The type of container used for storage