A major threat to the internal validity (esp. time-related threats and order effects) for pre-post designs can occur as it is impossible to
a. randomly assign participants.
b. counterbalance the order of treatments.
c. control for differential effects.
d. generalize the results.

Which of the following statements most accurately describes the requirement for the documentation of minors’ assent to participate in research? parents must approve written documentation. documentation is required unless waived by an irb. to protect minors documentation is always required. federal regulations do not require the documentation of minors’ assent.

Why was the leo frank case important ?

On average, being married has a(n) effect on happiness.