You Have Just Become a Lab Manager at a Prominent

Multiple Choice

You have just become a lab manager at a prominent infant lab. The lab has some old data with 6-month-old infants that were collected 10 years ago. Your task is to recruit a new group of 6-month-olds to compare to the original group. What concerns do you have about this comparison?

A) Attrition.
B) Cohort effects.
C) Both a and b.
D) None of the above.