The Table Below Shows the Mean Number of Daily Errors

question 80

Multiple Choice

The table below shows the mean number of daily errors by air traffic controller trainees during the first two weeks on the job.We want to perform a paired t-test at  = .05 to see if the mean daily errors decreased significantly. What would be the degrees of freedom for the appropriate test?

• A) 14
• B) 12
• C) 7
• D) 6

Grasp the concepts and implications of factorial designs in studying external validity.

Understand the concept of threats to internal validity and identify examples such as differential regression, compensatory equalization, and unreliable treatment implementation.

Comprehend the definition and implications of instrumentation in research studies.

Recognize threats to statistical conclusion validity including range restriction and understand how these threats affect the validity of research conclusions.