Web Activity 11.8 The impact of presuppositions

Discourse and Inference

A. Presuppositions in persuasive messages

The following examples represent the kind of technique commonly used in advertisements. For each one, identify the information that is being presupposed (there may be more than one presupposition in a single example). Why do you think that a creator of an ad might choose to express these ideas as presupposed, rather than simply asserting them?

  1. “The car that gets you where you’re going.”
  2. “It’s all about you—at last.”
  3. “When you’re ready to stop settling for second best . . .”
  4. “You deserve service worthy of royalty.”

B. Presupposition and belief

Does encoding an idea as presupposed rather than flat-out asserting it make it more believable, simply because it is presented as if it were uncontroversial and widely known? Set up an experiment to see if subtle wording changes make an idea easier to accept. You will tell your subjects that they are reading excerpts from newspaper articles (with names removed). Afterwards, you will ask them to take a test in which they report on their knowledge and beliefs.

The scale of your experiment may not be large enough to show any definitive results—for example, you would likely need to test a very large number of participants, using a larger number of examples than shown here, to be able to achieve statistically meaningful results. But even if your results are not conclusive, you will have the opportunity to think carefully about how such an experiment is set up.

Below are examples of three short passages, each appearing in two versions. In the A version, a targeted idea is presented in the form of a presupposition, whereas in the B version, the same idea is presented as an assertion.

Passage 1

  1. Affordability of education is a key concern for several of the candidates, including Congressman X. Many students find that the costs of an education quickly spiral out of control. The congressman is alarmed that more than 20% of students in the U.S. now declare bankruptcy within five years of graduation.
  2. Affordability of education is a key concern for several of the candidates, including Congressman X. Many students find that the costs of an education quickly spiral out of control. The congressman claimed that more than 20% of students in the U.S. now declare bankruptcy within five years of graduation.

Passage 2

  1. This volume offers more details on the War of 1812 than have been published previously, with copious citations and excerpts from historical documents. In it, the authors explain how the Americans lost this strategically critical war.
  2. This volume offers more details on the War of 1812 than have been published previously, with copious citations and excerpts from historical documents. In it, the authors write that the Americans lost this strategically critical war.

Passage 3

  1. The long-term research on the drugs has not been encouraging. Dr. X describes why it is that, despite a promising start, the anti-depression drugs known as SSRIs stop working over time for most people.
  2. The long-term research on the drugs has not been encouraging. Dr. X says that, despite a promising start, the anti-depression drugs known as SSRIs stop working over time for most people.

To perform the experiment, do the following:

  1. Create an additional three passages along these lines, each of them with A (presupposed) and B (asserted) versions.
  2. Create 12 filler items, written in a similar style, and of similar length. (You could base these on actual sentences drawn from news articles.)
  3. Create two separate reading sheets, so that each sheet contains three A version items and three B version items, with each subject seeing only one version of each passage. That is, set it up so that List 1 has 1A and 2B while List 2 has 1B and 2A, and so on.
  4. Randomize and intersperse the fillers and critical items.
  5. Create a test sheet that targets the presupposed/asserted content in each critical item. For example, for item 1:

             More than 20% of U.S. students file for bankruptcy within five years of graduation.
             In your opinion, is this statement true? Circle one number below:
             1  2  3  4  5  6  7
             1= definitely false
             7 = definitely true

    Pay special attention to fillers in your test. Remember that you need a mix of items, balanced between items that people will probably believe to be true, and items they will probably believe to be false.

  1. Administer your test and tabulate your results.
  2. Did you find any differences in responses to the presupposed versus asserted content? If so, what conclusions can you draw? If not, discuss what this might mean about presupposition, this specific experiment, and conditions under which presuppositions may or may not help to make ideas more believable.
Back to top