Scientific Method lesson

Independent Variables

A independent variable is the variable that the experimenter purposes changes or manipulates. The independent variable is the cause, input, or what is being done during the experiment.

Dependent Variables

A dependent variable is the variable that changes in response to the changes in the independent variable. The dependent variable is the effect, output, or what happens during the experiment.

Control variables (constant variables)

these are the elements that are kept the same during a scientific experiment. Any change to a controlled variable would invalidate the results.

Read the problems and identify the independent, dependent variable in each as well as constant variables.

Multiple Choice

The higher the temperature of the water, the faster the egg will boil. What is the Independent variable? (The 'cause' in a 'cause-effect' relationship)

• The temperature of the water

• The egg

• The time the egg takes to boil

• The type of egg

Multiple Choice

The higher the temperature of the water, the faster the egg will boil. What is the dependent variable (the effect)

• The egg

• The temperature of water

• The type of water

• The time it takes the egg to boil

Multiple Choice

Students of different age groups were asked to put the same jigsaw puzzle together, they were timed to see how long it took. What is the dependent variable?

• Age of students

• The jigsaw puzzle size

• The time to complete puzzle

• The music they listened to

Multiple Choice

Students of different age groups were asked to put the same jigsaw puzzle together, they were timed to see how long it took. What is the independent variable?

• The age of the student

• The jigsaw puzzle

• The time to complete puzzle

• The music they listened to

Multiple Choice

Which of the following is a testable hypothesis?

• Riding a bike is easier than riding a scooter.

• Increasing the amount of water will make plants grow taller.

• People prefer red apples over green apples.

• Elephants have a collective memory.

Multiple Choice

A scientist wants to investigate how different amounts of fertilizer affect the growth of sunflower plants. The experiment includes three groups of sunflowers. Group A receives no fertilizer. Group B receives low density fertilizer. Group C received high density fertilizer.

All pots are placed under the same conditions of sunlight, temperature, and watering schedule. The height of the sunflower plants is measured weekly for six weeks. What is the independent variable?

• Sunlight, temperature, and watering schedule

• Height of plants

• Type of fertilizer

• Group A

Multiple Choice

A scientist wants to investigate how different amounts of fertilizer affect the growth of sunflower plants. The experiment includes three groups of sunflowers. Group A receives no fertilizer. Group B receives low density fertilizer. Group C received high density fertilizer.

All pots are placed under the same conditions of sunlight, temperature, and watering schedule. The height of the sunflower plants is measured weekly for six weeks. What is the dependent variable?

• Sunlight, temperature, and watering schedule

• Height of plants

• Type of fertilizer

• Group A

Multiple Choice

A scientist wants to investigate how different amounts of fertilizer affect the growth of sunflower plants. The experiment includes three groups of sunflowers. Group A receives no fertilizer. Group B receives low density fertilizer. Group C received high density fertilizer.

All pots are placed under the same conditions of sunlight, temperature, and watering schedule. The height of the sunflower plants is measured weekly for six weeks. What are the constants?

• Sunlight, temperature, and watering schedule

• Height of plants

• Type of fertilizer

• Group A

• Collect data: Quantitative or Quantitative

• ​Analyze data to draw conclusion

​Make Observations

• Evaluate the date and conclusions presented by other scientists.

• Determine the validity of hypothesis

• Explains results

Make Conclusion

• Document results

​Communicate

Results​

Multiple Choice

A testable prediction about a scientific investigation is a(n)

• Question
• Observation
• Hypothesis
• Experiment

Multiple Choice

Susan said, “If I fertilize my geranium plants, then they will have more flowers.”

• recognize a problem

• test the hypothesis with an experiment

• form a hypothesis

• draw conclusions

Multiple Choice

A series of steps used by scientists to solve a problem or answer a question. 

• scientific method
• recipe
• data collection
• metric system

Multiple Choice

Which is NOT a step in the scientific method?

• Make observation
• Form a theory
• Collect data
• Form a hypothesis

Multiple Choice

Should experiments be repeated over and over to see if the results are the same each time?

• yes
• no

Multiple Choice

Which variable happens in a condition that is manipulated, or changed.

• Dependent Variable

• Independent Variable

Multiple Choice

Descriptive data that includes sights, sounds, and smells.

• Quantitative Data

• Qualitative Data

Multiple Choice

Research Question: Does the type of gasoline put in a car effect how fast the car can drive?

What is the independent variable?

• Type of gasoline
• which car the gas is put into
• how fast the car can drive
• how much gas is put into the car

Multiple Choice

What is the DEPENDENT variable (effect) in this experiment?

"Does eating breakfast improve test scores?"

• eating breakfast or not

• the grade you got on the test

• what time you get up in the morning

• how tasty the breakfast is

Multiple Choice

What is the variable called that is used for comparison (does not change)?

• Changed

• Control
• Independent Variable
• Dependent Variable