Experimental Design Scenarios

Scenario: Chloe is completing an investigation where she is studying the relationship between the volume of water a plant gets per day and the photosynthesis rate of the plant. She gives one plant 1 mL of water per day and the other plant 5 mL of water per day. She measures oxygen production every other day for the photosynthesis rate.

What is the INDEPENDENT variable?

• The volume of water

• The photosynthesis rate

• Oxygen production

• Types of plants

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-1

Scenario: Chloe is completing an investigation where she is studying the relationship between the volume of water a plant gets per day and the photosynthesis rate of the plant. She gives one plant 1 mL of water per day and the other plant 5 mL of water per day. She measures oxygen production every other day for the photosynthesis rate.

What is the DEPENDENT variable?

• The volume of water

• The height of the plant

• Oxygen production

• Types of plants

Tags

NGSS.MS-LS2-1

Scenario: Chloe is completing an investigation where she is studying the relationship between the volume of water a plant gets per day and the photosynthesis rate of the plant. She gives one plant 1 mL of water per day and the other plant 5 mL of water per day. She measures oxygen production every other day for the photosynthesis rate.

What is one possible CONTROLLED VARIABLE Chloe should have in her investigation?

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-1

Scenario 2: Vivi is comparing the effect of different fertilizers - food compost and commercial fertilizer - on plant growth. The plants were fertilized as follows: Flat A received 10 grams of commercial fertilizer; Flat B received 10 grams of food compost; and Flat C received no fertilizer. At the end of 20 days, Vivi recorded the height of the plants in centimeters.

What is the INDEPENDENT variable?

• Amount of fertilizers

• Types of fertilizers

• Height of the plant

• Type of plant

Scenario 2: Vivi is comparing the effect of different fertilizers - food compost and commercial fertilizer - on plant growth. The plants were fertilized as follows: Flat A received 10 grams of commercial fertilizer; Flat B received 10 grams of food compost; and Flat C received no fertilizer. At the end of 20 days, Vivi recorded the height of the plants in centimeters.

What is the DEPENDENT variable?

• Amount of fertilizers

• Types of fertilizers

• Height of the plant

• Type of plant

Tags

NGSS.MS-LS2-1

Scenario 2: Vivi is comparing the effect of different fertilizers - food compost and commercial fertilizer - on plant growth. The plants were fertilized as follows: Flat A received 10 grams of commercial fertilizer; Flat B received 10 grams of food compost; and Flat C received no fertilizer. At the end of 20 days, Vivi recorded the height of the plants in centimeters.

Which Flat can be considered the CONTROL GROUP (aka placebo group)?

• Flat A

• Flat B

• Flat C

• None

Scenario 2: Vivi is comparing the effect of different fertilizers - food compost and commercial fertilizer - on plant growth. The plants were fertilized as follows: Flat A received 10 grams of commercial fertilizer; Flat B received 10 grams of food compost; and Flat C received no fertilizer. At the end of 20 days, Vivi recorded the height of the plants in centimeters.

What is one CONTROLLED VARIABLE that Vivi used in her investigation?

Tags

NGSS.MS-LS2-1

Scenario 3: Domo is investigating which types of insulation transfers the least heat. She tested 4 different types of insulation (A, B, C, and D). She filled each of the jars half-full with water and 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?

• Temperature of water

• Types of plastic lids

• Amount of water

• Types of insulation

Scenario 3: Domo is investigating which types of insulation transfers the least heat. She tested 4 different types of insulation (A, B, C, and D). She filled each of the jars half-full with water and 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 DEPENDENT variable?

• Temperature of water

• Types of plastic lids

• Amount of water

• Types of insulation

Tags

NGSS.MS-PS3-4

Scenario 3: Domo is investigating which types of insulation transfers the least heat. She tested 4 different types of insulation (A, B, C, and D). She filled each of the jars half-full with water and 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.

How could Domo use a CONTROL GROUP (aka placebo group) in this investigation?