If a group of potential participants is tested so those scoring ...

[Caiter2013]

If a group of potential participants is tested so those scoring poorly can be selected for participation in a program to raise test scores, the selected group may show higher scores after engaging in the program.
 
  There would be a threat to internal validity here. It would be
  a. selection.
  b. maturation.
  c. statistical regression.
  d. history.

Question 2

If research participants are assessed with a particular questionnaire early in a study, but the researchers change the questions for later assessment so participants can't simply repeat answers,
 
  what potential thread to internal validity would be at work here?
  a. instrumentation.
  b. testing.
  c. selection.
  d. history.

[hanadaa]

Answer to Question 1

c

Answer to Question 2

a