Imagine That a Study Has Just Been Published Which Shows

question 514

Multiple Choice

Imagine that a study has just been published which shows a relationship between a certain nutritional supplement and a lower incidence of cold and flu. This study was based on survey data and asked people to report whether or not they used this supplement in the last four months, as well as estimate the amount of times they were ill in that same period, and the average duration associated with those illnesses. Their results show that people who take the supplement report being ill less often and/or for less time. The company selling the supplement wants to claim that this is scientific proof their product works. Which of the following is not a possible alternative explanation to the idea that the supplement reduces frequency and/or duration of illness?

• A)placebo effect
• B)the third-variable problem
• C)the bidirectionality problem
• D)all of the above are plausible alternative explanations
• E)none of the above are plausible alternative explanations

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Definitions:

Caudal Vein

A vein located in the tail region of animals, especially noted in veterinary contexts, facilitating blood return from the tail.

Posterior Vena Cava

The large vein that carries deoxygenated blood from the lower and middle body into the heart.

Hepatic Portal Vein

The hepatic portal vein is a blood vessel that carries blood from the gastrointestinal tract and spleen to the liver, transporting nutrients and toxins for processing.

Saphenous Vein

A large vein running along the length of the leg, often used for grafts in coronary artery bypass surgery.