Replication
The final component of experimental design that we will explore is replication. In addition to random assignment, replication helps ensure that the results of an experiment are truly caused by the change in the factor of interest and not by other hidden factors or natural variation in data. A good experiment always achieves replication by including large numbers of participants, but replication can also be achieved by repeating the entire experiment with new groups of participants. As you will learn in future lessons, certain statistical analyses can only be performed if the sample meets a minimum size requirement.
See the example below for a summary of replication, then answer Question 5.
example
Fill in the blanks to complete these sentences.
Replication helps ensure that the results of an experiment are truly caused by ________________________ and not by ____________________________. A good experiment can achieve replication by ________________________ or by _______________________________.
Now you try it. Use the information you found above to help you answer Question 5.
question 5
Which form of replication is demonstrated in the previous fish experiment?
- a) Many participants included in one experiment
- b) The experiment repeated with different participants
Looking ahead
In the upcoming activity, you will design an experiment to study the health of coral reefs in our oceans. Use the National Ocean Service website provided here to learn some basic facts about coral, then record your responses to Question 6. Make sure to have your responses available during the activity.
Read the article on this webpage (make sure to read the “Did you know?” section!) then answer Question 6.
https://oceanservice.noaa.gov/facts/coral.html.
Question 6
Answer the following questions. Don’t forget to have your answers available during the upcoming activity!
Part A: Is coral a plant? An animal? Both?
Part B: What are some factors that impact the health of coral reefs?
Part C: What is coral bleaching?
