Control groups are typically used to address threats to a) ...

[segrsyd]

Control groups are typically used to address threats to
 
  a) External validity
  b) Ecological validity
  c) Construct validity
  d) Internal validity

Question 2

Ceiling and floor effects refer to
 
  a) The minimum and maximum goals of treatment
  b) Limits to the amount of change possible
  c) Top and bottom scoring participants
  d) A measure with a range of possible scores that is too great to detect an effect

[karmakat49]

Answer to Question 1

Correct Answer: d

Answer to Question 2

Correct Answer: b