Researchers randomly assigned adolescents to either a single-grade classroom or a mixed-grade classroom, then measured several learning outcomes in each group. This is an example of a ________.
A. naturalistic observation
B. case study
C. natural experiment
D. field experiment
Answer:D
Researchers randomly assigned adolescents to either a single-grade classroom or a mixed-grade classroom, then measured several learning outcomes in each group. This is an example of a ________.
A. naturalistic observation B. case study C. natural experiment D. field experiment