Question

A researcher conducted a study to determine if aspirin reduces the chance of a heart attack. He randomly assigned 250 patients to take aspirin every day and 250 patients to take a placebo every day. After a certain length of time he reported the number of heart attacks in the patients who took aspirin every day and in those who did not take aspirin every day.

What is the most important reason for the researcher to randomly assign patients to one of the two groups?

Group of answer choices

a. So that the groups are similar, or have no real difference, prior to the treatment.

b. So that there is an equal number of people in both groups for the experiment.b.

c. So that equal amounts of aspirin and placebo would be used during the experiment.

d. So that the results of the study will generalize.

* I'm noticing various answers to this question on Chegg, and asking for clarification on the correct answer.

Answer 1

After the researcher has formulated the hypothesis that whether asprirn reduces the cance of heart attack, and selecting the participants for experiment has done, the researcher has to assign them into groups. By randomly assigning the participants into groups, the experimenters can be fairly sure that each group will be the same before the independent variable is applied.Participants might be randomly assigned to the control group, which does not receive the aspirin. Or they might be randomly assigned to the experimental group, which does receive the aspirin.

The random Assignment is done in order to generalize the results of an experiment to a larger group, so that any changes that occurs can be assumed to be the result of the treatment of interest i.e. aspirin.

Hence option (d) is the most important reason for the researcher to randomly assign patients to one of the two groups.