An airport administrator investigated the attention span of air traffic controllers to determine how many

incoming flights the average controller could coordinate at the same time. Each randomly selected

controller was tested without his or her knowledge by a computer program which fed false flight

Information to a computer terminal. The controller first “received” information from one plane and by the

end of the hour was coordinating the flight pattern of ten planes simultaneously. The administrator

analyzed the errors collected by the computer program. The analysis revealed that six was the maximum

number of planes a controller could handle without making potentially fatal errors. Also, no errors

occurred when only one to three planes were incoming. He concluded that a controller should never

coordinate more than six incoming flights.

Are the researcher’s conclusions warranted (yes/no)? ____________

Name the independent variable(s):

Name the dependent variable(s):

Name the confounded variable(s):

What is one method to “unconfound” the experiment?