To study the effects of aging, Professor Drake compares the ...

[Arii_bell]

To study the effects of aging, Professor Drake compares the reaction times of 60-year-olds with those of 30-year-olds. She tests all younger subjects in the morning, and all older subjects in the afternoon.
 
  She concludes that aging causes a decline in the speed of responses. This study lacks ________ because of potential ________.
  A) external validity; demand characteristics
  B) external validity; confounds
  C) internal validity; demand characteristics
  D) internal validity; confounds

Question 2

Which of the following could be considered a limitation to the experimental method?
 
  A) The laboratory settings can be very artificial.
  B) The researcher can't make causal statements.
  C) The researcher has very little control over what happens in the study.
  D) The researcher can't manipulate the independent variable.

[lkanara2]

Answer to Question 1

Answer: D

Answer to Question 2

Answer: A