Question

A recent research study randomly divided participants into groups who were given different levels of Vitamin E to take daily. One group received only a placebo pill. The research study followed the participants for eight years to see how many developed a particular type of cancer during that time period.

Which of the following responses gives the best explanation as to the purpose of randomization in this study?

A. To increase the accuracy of the research results
B. To ensure that all potential cancer patients had an equal chance of being selected for the study.
C. To reduce the amount of sampling error.
D. To produce treatment groups with similar characteristics.
E. To prevent skewness n the results.

Answer 1

D. To produce treatment groups with similar characteristics.

Explanation:

Random Assignment is the process of classifying the participants into groups. A group such as the one in the question could be classified into the treatment or experimental groups and the placebo groups. The importance of random assignment is to ensure that any differences in the group is as a result of the treatment and not any other factor. Therefore the participants must have similar characteristics so that any observed differences in the experiment, can be attributed to the treatment.

Random selection is used by experimenters in research work for the purpose of ensuring that all members of the group have an equal chance of being selected as participants of the study. In this instance, the researcher is trying to ensure that the number of participants in the study is a true representation of the entire population.