In the fall semester, a professor compared a lecture approach to ...

[bobthebuilder]

In the fall semester, a professor compared a lecture approach to teaching statistics (using a sophomore class) with a problem-oriented approach (using a senior class). Both sections were given the same final exam. The professor repeated the same experiment in the spring semester. This study shows a confounding of
 
  a. test scores with teaching approaches.
  b. class levels with test scores.
  c. teaching approaches with class level.
  d. semester with teaching approaches.

Question 2

Selection bias is a threat to internal validity arising from failure to use
 
  a. a control group. c. reliable measuring instruments.
  b. counterbalancing across conditions. d. random assignment.

[perkiness]

Answer to Question 1

C

Answer to Question 2

D

[bobthebuilder]

Thanks for the timely response, appreciate it

[cassie_ragen]

Gracias!