Nature of Science

Scientists frequently repeat the experiments of others scientists. Why is this important in science?

• Scientists often ask each other for help in performing experiments.

• Replication of experiments helps to confirm and verify results.

• Scientists frequently perform other scientists’ experiments in order to practice their technique.

• Repeating experiments is an effective way to make sure a laboratory is in optimal condition.

Cara read an article on why repetition and replication are so important, but she did not understand the difference between them. Which of the following best explains the two terms?

• Repetition is when a scientist repeats an experiment; replication is when a scientist conducts an experiment on genetic material.

• Repetition is when a scientist does the same experiment a number of times; replication is when other scientists reproduce a scientist’s experiment.

• Repetition is when a scientist publishes in more than one scientific periodical; replication is when another scientist reproduces another scientist’s results.

• Repetition is when a scientist commits an error in an experiment the first time and must repeat it; replication is when a scientist repeats an experiment to make sure it is valid.

Kaylee reads an article that states that the frequency of chirping by crickets is related to the temperature of

their environment. She wants to conduct an experiment to see if this is true. Kaylee states this hypothesis:

Crickets chirp more frequently when the temperature of their environment increases. What is the test

variable (independent variable) and outcome variable (dependent variable) in Kaylee’s experiment?

• a.test variable (independent variable): number of crickets; outcome variable (dependent variable): frequency of chirping

• b. test variable (independent variable): temperature of environment; outcome variable (dependent variable): frequency of chirping

• c. test variable (independent variable): number of crickets; outcome variable (dependent variable): temperature of environment

• d. test variable (independent variable): frequency of chirping; outcome variable (dependent variable): temperature of environment

What step does every scientific experiment begin with?

• hypothesis

• question/problem

• procedures

• conclusion

The independent variable is the ONE thing you _____.

• change on purpose
• control or keep constant
• measure

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-4

The variable that is being measured or observed is called the _______________. Hint: this is the variable that is the result or effect

• independent variable

• dependent variable

• control variable

What is a constant/control in an experiment?

• Things that do not change in a experiment. It's the variable that stays the same. You can have many variables stay the same.

• It's the variables that the scientist changes in the experiment

• It's the variables that are being measured in an experiment

What is being changed in this experiment?

• ramp height
• the speed that the ball rolls
• type of ball

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-1

What is being kept constant?

• ramp height
• speed of the ball rolling
• type of ball

Tags

NGSS.3-5-ETS1-3

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

• scientific method
• recipe
• data collection
• metric system

Tags

NGSS.MS-ESS2-5