Experimental Design

The parts of the experiment that must be kept the same.

• independent variable

• what is measured or observed during the experiment

• constants

• what is kept the same throughout all trials

• dependent variable

• what the experimenter manipulates/changes

Maya designed an experiment to answer the following question:

How does the amount of water given to a lima

bean seed affect how tall it grows?

1. 1. What is the independent variable?​ (a)  

2. 2. What is the dependent variable? ​​ (b)  

• the kind of plant

• the type of soil

• the amount of sunlight it gets

• water amount
• how tall the plant grows

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

Maya designed an experiment to answer the following question:

How does the amount of water given to a lima

bean seed affect how tall it grows?

Which of the following are constants needed for this experiment to be accurate?

• the kind of plant

• the type of soil

• the amount of sunlight it gets

• water amount
• how tall the plant grows

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

How many variables should you change in an experiment?

• none
• only 1

• 2 or more
• depends on the type of experiment

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.

Thomas tests different types of liquids to see which will grow his plants the most. He has water, soda, milk, and no liquid at all. What is the control group?

• the one with water

• the one with soda

• the one with milk

• the one with no liquid

Three baseball players investigate to see who can throw a baseball the farthest. They mark off an area on the playground for their investigation. Which should they keep constant?

• height of the players
• color of the balls thrown
• order in which the players throw
• spot from which the players throw

Tags

NGSS.MS-PS2-2

Dory set up an experiment to see how the mass of a ball affects the distance it rolls off a ramp. What is the dependent variable?

• distance traveled by the ball
• height of the ramp
• mass of the ball
• ball type

Tags

NGSS.MS-PS2-2

What is the factor that an experimenter changes on purpose?

• Dependent Variable
• Independent Variable
• Constant
• Control

In this graph, what is the dependent variable? 

• Day of the week

• number of muffins sold