How should the control group be selected? a) Control group ...

[ss2343]

How should the control group be selected?
 
  a) Control group should enroll in treatment for the characteristic of interest.
  b) Control group should vary randomly on the characteristic of interest.
  c) Control group should allow the investigator to isolate the characteristic of interest.
  d) Control group should allow the investigator to statistically control for the characteristic of interest.

Question 2

How might the selection of groups in observational studies affect the construct validity of the study?
 
  a) Populations sampled from might be too general.
  b) Populations sampled from might not be representative.
  c) Subjects' status on the characteristic of interest might vary systematically.
  d) Subjects might show random variation on other characteristics of interest.

[joechoochoy]

Answer to Question 1

Correct Answer: c

Answer to Question 2

Correct Answer: b

[ss2343]

Great answer, keep it coming

[peter]

Excellent