A researcher reports that there is no consistent relationship ...

[mydiamond]

A researcher reports that there is no consistent relationship between grade point average and the number of hours spent studying for college students. The correlation between grade point average and the number of hours studying is an example of a ____.
 
  a. positive correlation
 b. negative correlation
  c. correlation near zero
  d. correlation near one

Question 2

What are the strengths of the switching-replications design with respect to threats to internal validity and why does it have these strengths?
 
  What will be an ideal response?

[Jevvish]

Answer to Question 1

c

Answer to Question 2

In randomized experiments, especially when the groups are aware of each other, there is the potential for social threats to internal validity; compensatory rivalry, compensatory equalization, and resentful demoralization are all likely to be present in educational contexts where programs are given to some students and not to others. The switching-replications design helps lessen these threats because it ensures that everyone will eventually get the program. Additionally, it allocates who gets the program first in the fairest possible manner, through the lottery of random assignment.