A researcher wishes to study the relationship between the level of background noise and mental concentration. The treatment (noise level) will have three levels: no noise, low-intensity noise, and high-intensity noise. the subjects are to be divided into three groups, and each group is to receive one of the treatments. He has available to him a set of 60 female volunteers and a set of 90 male volunteers. What experimental design strategy would help him eliminate the introduction of gender as a confounding variable?
A)stratified sampling
B)replication
C)blocking
D)systematic sampling
E)double-blind trials

Question

A researcher wishes to study the relationship between the level of background noise and mental concentration. The treatment (noise level) will have three levels: no noise, low-intensity noise, and high-intensity noise. the subjects are to be divided into three groups, and each group is to receive one of the treatments. He has available to him a set of 60 female volunteers and a set of 90 male volunteers. What experimental design strategy would help him eliminate the introduction of gender as a confounding variable? ​
A)stratified sampling
B)replication
C)blocking
D)systematic sampling
E)double-blind trials

Quizplus · Accepted Answer

Blocking is the correct strategy to eliminate the introduction of gender as a confounding variable. By dividing subjects into blocks based on gender before assigning them to treatment groups, the researcher can ensure that gender does not influence the results related to the effect of noise level on mental concentration.

A Researcher Wishes to Study the Relationship Between the Level