Professor Higgins is concerned about the findings of a longitudinal study on childhood depression that she conducted between 1985 and 2015 in New York because many of the participants witnessed the terrorist attacks on the World Trade Center. Professor Higgins is concerned about __________ effects.
A) practice
B) cross-sectional
C) dropout
D) cohort
Question 2
Bernadette, a participant in a longitudinal study, became quite familiar with the test over time and, as a result, her performance improved. This limitation of longitudinal research is known as __________.
A) biased sampling
B) practice effects
C) random assignment
D) cohort effects