Teaching Argumentation. Julia A. Simms
making the argument.
Examine Motives
The final step in evaluating persuasive rhetoric is to examine the speaker’s motives. Students can do this by asking the question, “What principles underlie the speaker’s logic?” To determine the logic behind a speaker’s perspective, students can make generalizations that highlight how the speaker is moving from his or her claim to grounds. For example, in the previous claim about banning smoking (see figure I.5, page 35), students might observe that the speaker is using logic such as the following to generate grounds for his or her claim:
If a speaker’s logic was that people have the right to do certain things, even if those things might hurt them, students could infer that the principle of personal freedom is a primary consideration for the speaker. If a speaker’s logic involved the idea that people should not be allowed to do things that hurt other people, students might infer that while personal freedom is important to the speaker, it does not extend to situations where others might be hurt. Finally, from the speaker’s logic that it is okay for the government to make money off something that hurts people, students might conclude that the speaker is motivated by economic motives, rather than altruistic ones.
Identifying Errors in Reasoning
Students can analyze a claim or evidence and decide whether it is logical by identifying errors in reasoning. To guide students in identifying errors in reasoning, teachers can use the following process:
1.Explain the different types of errors.
2.Give students practice exercises for identifying errors.
The following sections expand on these steps.
Explain the Different Types of Errors
Over time, 20th century philosophers (Johnson-Laird, 1983; Johnson-Laird & Byrne, 1991; Toulmin, Rieke, & Janik, 1981) have identified a number of common—yet fallacious—lines of thinking and arguing. Marzano (2007) classified them into four main categories:
1.Faulty logic
2.Attack
3.Weak reference
4.Misinformation
Errors of faulty logic occur when someone uses incorrect premises or unsound reasoning to make claims or draw conclusions. To illustrate, consider the following claim: “Mark will probably want to watch the football game because he is a boy.” The underlying premise of this claim—that all boys enjoy watching sports—is incorrect. Some boys enjoy sports; others do not. Therefore, the claim makes an error of faulty logic. Attack refers to the use of irrelevant and often personal information to undermine an argument. For example, claiming that every argument a specific politician makes is necessarily flawed because he once had an affair is committing an error of attack. Using weak reference simply means that unreliable or untrustworthy sources were used, and misinformation means that information was incorrect or used incorrectly. Table I.18 lists specific logical errors and organizes them into the aforementioned four categories.
Table I.18: Four Categories of Errors in Reasoning
| Type Error of | How the Error Can Occur |
| Faulty Logic | Contradiction: Presenting conflicting information |
| Accident: Failing to recognize that an argument is based on an exception to a rule | |
| False Cause: Confusing a temporal (time) order of events with causality or oversimplifying the reasons behind an occurrence | |
| Begging the Question: Making a claim and then arguing for the claim by using statements that are simply the equivalent of the original claim | |
| Evading the Issue: Changing the topic to avoid addressing the issue | |
| Arguing From Ignorance: Arguing that a claim is justified simply because its opposite has not been proven true | |
| Composition: Asserting something about a whole that is really only true of its parts | |
| Division: Asserting something about all of the parts that is generally, but not always, true of the whole | |
| Attack | Poisoning the Well: Being so completely committed to a position that you explain away absolutely everything that is offered in opposition to your position |
| Arguing Against the Person: Rejecting a claim using derogatory facts (real or alleged) about the person who is making the claim | |
| Appealing to Force: Using threats to establish the validity of a claim | |
| Weak Reference | Sources That Reflect Biases: Consistently accepting information that supports what we already believe to be true or consistently rejecting information that goes against what we believe to be true |
| Sources That Lack Credibility: Using a source that is not reputable for a given topic | |
| Appealing to Authority: Invoking authority as the last word on an issue | |
| Appealing to the People: Attempting to justify a claim based on its popularity | |
| Appealing to Emotion: Using a sob story as proof for a claim | |
| Misinformation | Confusing the Facts: Using information that seems to be factual but that has been changed in such a way that it is no longer accurate |
| Misapplying a Concept or Generalization: Misunderstanding or wrongly applying a concept or generalization to support a claim |
Source: Adapted from Marzano, 2007.
As Marzano and Heflebower (2012) pointed out, students will frequently encounter errors in reasoning on television, on the Internet, and in other forms of media. To argue effectively, students must be aware of various reasoning errors in order to evaluate their own thinking, as well as the claims of others. To develop this awareness, students can practice identifying the different kinds of errors.
Practice Exercises for Identifying Errors