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To study the effects of noise on worker productivity, researchers have on group of subjects work in a noisy room and a second group work in a quiet room. To ensure that any differences in the productivity of the two groups actually results from the different noise levels to which the groups are exposed, the researchers would use:
1) the case study
2) correlational measurement
3) naturalistic observation
4) replication
5) random assignment
Answer:
Researchers should use 5) Random assignment.
Explanation:
According to the description, the experimental design is being used to study the effects of noise on worker productivity. The most common form for experimental design happens by dividing participants into two groups, the experimental group and the control group. Change - the noisy room, in this case - is only introduced to the experimental group. Now, if researchers want to be sure that any differences in the productivity actually result from the different noise levels, they should use random assignment. That means giving every participant equal chances of being randomly assigned to each group. Random assignment is also called random allocation or randomization.
