V05-04

Official Solution:


In a recent experiment to test the hypothesis that expectation influences the experience of flavor, researchers conducted a taste test involving over 200 participants. Each participant tasted two versions of a cola beverage. The standard recipe was used for both versions, with the only modification being the addition of white vinegar to one version. Participants were informed that one of the versions contained a “secret taste-enhancing ingredient.” Contrary to the researchers' initial expectations, the majority of participants selected the white vinegar version as the tastier one. Given that white vinegar was the only variable introduced and was not commonly perceived as a desirable ingredient in cola, researchers concluded that the hypothesis—that expectation can significantly influence flavor perception—was correct.

Which of the following is an assumption that the researchers did not need to make to arrive at their conclusion?


A. The participants did not ordinarily prefer a cola beverage mixed with white vinegar.
B. Participants believed that they could distinguish the beverage with the 'secret ingredient' based on its flavor.
C. A noticeable amount of vinegar was added to one version of the cola to ensure it could potentially influence flavor perception.
D. Study participants were not selected based on their preference for the taste of white vinegar.
E. Cola recipes do not contain other taste-enhancing ingredients.


Premise 1: Participants were told that there is a taste-enhancing ingredient in one of the beverages.

Premise 2: Participants considered the beverage with the ingredient tastier, although the ingredient was white vinegar, which few people would choose to add..

Conclusion: Expectation influences experience.

A. One underlying assumption to the conclusion is that the participants do not ordinarily find white vinegar tasty. They found it tasty only because they were suggested that it was so. If they ordinarily found it tasty, then it was not because of the suggestion that they found it tasty and hence the conclusion could not have been drawn.

B. If the participants could not really identify the beverage with the extra ingredient, then their selection must have been only random and they did not really find the beverage with white vinegar tasty; thus the conclusion of the researchers would be wrong. Since negating this option breaks down the argument, this option must be an assumption.

C. This option can be eliminated using a similar reasoning as B. Saying that the amount of vinegar is insignificant is equivalent to saying that the participants could not really identify the beverage with the extra ingredient.

D. This option can be eliminated using a similar reasoning as A. If the participants were selected because they preferred the taste of white vinegar, the argument breaks down because of the reason described in A above. Hence D must be an assumption.

E. CORRECT This option is not a required assumption because even if the cola contained taste-enhancing ingredients, they would be present in both versions of the drink. We know from the passage that the same cola was used before one of the beverages was tainted with vinegar as the "special ingredient". Vinegar is the only difference between the two beverages.


Answer: E