If a human observer becomes more proficient in the course of a study, the type of threat to internal validity is called a change in
A) proficiency.
B) instrumentation.
C) research bias.
D) regression to the mean.
Question 2
The concept of regression to the mean suggests
A) participants with extreme scores will score more extreme on a second test.
B) scores of participants on a second test would be the same or similar to the first test.
C) scores of participants on a second test would be less extreme on average on a second test.
D) None of the above