A threat to internal validity in which extreme scores, upon ...

[asd123]

A threat to internal validity in which extreme scores, upon retesting, tend to be less extreme is called:
 
  a. a time-series confound.
  b. a single-group effect.
  c. regression to the mean.
  d. none of the alternatives is correct.

Question 2

Students in two of Mr. Lewis's classes are given a test to assess their knowledge of world geography. Then, students in one of the classes participate in Mr. Lewis's new interactive geography learning modules. Students in the other class learn geography using the traditional lecture method. After three months, all students once again take a test to assess their knowledge of world geography. What kind of design did Mr. Lewis use?
 
  a. single-group pretest-posttest
  b. non-equivalent control group pretest-posttest
  c. multiple-group time-series design
  d. single-group time-series design

[karmakat49]

Answer to Question 1

c

Answer to Question 2

b

[asd123]

Thanks for the timely response, appreciate it

[parker125]

Excellent