Experimental Design

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

• Constants
• Independent variable

• Dependent variable

• Conclusion

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?

In this experiment, what variable should Maya CHANGE?

• the amount of water

• the kind of plant

• the type of soil

• the amount of sunlight it gets

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

Esther became interested in insulation while her parent’s new house was being built. She decided to determine which insulation transferred the least heat. She filled each of 5 jars half-full with water.

She sealed each jar with a plastic lid.Then she wrapped each jar with a different kind of insulation. She put the jars outside in the direct sunlight. Later, she measured the temperature of the water in each jar. What is the independent variable?

• The type of insulation

• The temperature of the water

• Number of houses

• The amount of sunlight

Tags

NGSS.MS-PS3-3

NGSS.MS-PS3-4

Why is the placebo effect used?

• To compare results between the real medicine and placebo

• To make new medicine

• To train doctors

• To make food

How many variables should you change in an experiment?

• none
• only 1

• 2 or more
• depends on the type of experiment

The type of variable that responds to the experiment and is what you measure or count to determine if your hypothesis is true.

• Independent
• Dependent
• Control

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

Cindy wanted to find out how the amount of sunlight affects the growth of plants. She placed a tomato plant in 6 identical 10 inch pots with the same amount and type potting soil. She watered them ¼ cup each day. 3 plants were placed under a cardboard box and 3 plants were placed in the sunlight. She measured the growth of the plant each week for three weeks.

What is the dependent variable?

• Using the same type of plant

• Each plant was placed in a 10 inch pot

• The growth of the plant

• 3 plants in the sunlight and 3 plants under a box

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-4