Question

Thirty-six students at a local middle school were randomly selected to participate in a taste test to select a new menu item for a cafeteria. Each student was given a choice between the macaroni and cheese and the Cajun potato barrels. From the sample, 20 students selected macaroni and cheese and 16 students chose the Cajun potato barrels. Each student was asked to rate the item they chose on a scale from 1 (extremely dislike) to 9 (extremely like). Which of the following prevents this study from being a well-designed experiment?A)There was no replication because students did not eat both menu items.B)The treatments (new menu item) were not randomly assigned to the students.C)An item that is currently on the menu should have been used as a control.D)Students should not have been randomly selected.E)There were no problems, and the study was a well-designed experiment.

Answer 1

The treatments (new menu item) were not randomly assigned to the students - option B.

Explanation:

A choice was given to each student to select between the macaroni and cheese and the Cajun potato barrels. Therefore, the treatments were not randomly assigned to the students, and students who prefer their food will select that item and give high ratings. Hence, the study suffers from selection bias.

The reason below prevents this study from being a well-designed experiment;

The treatments (new menu item) were not randomly assigned to the students - option B.