I. Lesson preparation
Chapter 7: The Worth of Personal Experience, Case Examples, Testimonials, and Statements of Authority as Evidence
What are evidences?
Evidence is explicit information shared by the communicator that is used to back up or to justify the dependability of a factual claim. In prescriptive arguments, evidence will be needed to support reasons that are factual claims; in descriptive arguments, evidence will be needed to directly support a descriptive conclusion.
Major kinds of evidence
a) Personal experiences
Phrases like "I know someone who..." and "In my experience, I've found..."
Fallacy: Hasty Generalization: A person draws a conclusion about a large group based on experiences with only a few members of the group
b) Case examples
A detailed catchy description of, or story about, one or several individuals or events to support a conclusion
Descriptions are usually based on observations or interviews
c) Testimonials
They quote particular persons, often a celebrity, as saying that a given idea or product is good or bad, or that extraordinary events have occurred, based upon their personal experiences -> Personal testimonials
d) Appeals to authorities or experts
Such appeals potentially provide more oomph to an argument than testimonials, depending on the background of the authority
Authorities are often wrong
Need to ask, "Why should we believe this authority?"
You should strive to learn as much as you can about the purpose of Websites, the credentials and experience of the contributors associated with them, and the nature of the reasoning support provided for their conclusions.
seek out evidence on the same topic from other sites.
Chapter 8: How Good Is the Evidence: Personal Observation and Research Studies?
e) Personal observations
Observers, unlike certain mirrors, do not give us "pure" observations
What we "see": a set of values, biases, attitudes, pior experiences, previous training, and expectations
Reports of observations in newspapers, magazines, books, television, and the Internet, as well as in research studies, are used as evidence,
Biased surveys and questionnaires
You cannot assume that survey responses accurately reflect true attitudes.
First, for survey responses to be meaningful, they must be answered honestly.
Second, many survey questions are ambiguous in their wording; the questions are subject to multiple interpretations.
Third, surveys contain many built-in biases that make them even more suspect.
Another important contextual factor is length. In long surveys, people may respond differently to later items than to earlier items simply because they get tired.
f) Research studies
"Studies show..."
"Research investogators have found in a recent survey that..."
Research studies that systematically collect observations by people trained to do scientific research are one form of authority.
publicly verifiable data—that is, data obtained under conditions such that other qualified people can make similar observations and get the same results.
control—that is, the use of special procedures to reduce errors in observations and in the interpretation of research findings.
Precision in language. Concepts are often confusing, obscure, and ambiguous. Scientific method tries to be precise and consistent in its use of language.
Fallacy: Impossible Certainty: Assuming that a research conclusion should be rejected if it is not absolutely certain
PROS
+ Scientific research is subject to public verifiability.
+ Research uses control to minimize extraneous factors.
+ Scientific research is precise and consistent in the use of language.
CONS
+ Research varies greatly in quality and artificiality.
+ Research findings often contradict one another and facts can change over time.
+ Research findings can only support conclusions.
+ Scientific research is a human activity; it can be distorted and is not free of subjectivity.
g) Anologies
Communicators often use resemblance as a form of evidence.
An argument that uses a well-known similarity between two things as the basis for a conclusion about a relatively unknown characteristic of one of those things is an argument by analogy.
Analogies both stimulate insights and deceive us.
Evaluating Analogies
The number of ways the two things being compared are similar and different.
The relevance of the similarities and the differences.
Faulty Analogy: Occurs when an analogy is proposed in which there are important relevant dissimilarities.
II. Post-class reflection
In descriptive arguments, evidence will be needed to directly support a descriptive conclusion.
In prescriptive arguments, evidence will be needed to support reasons that are factual claims.
III. Application
Give at least one specific example of an aspect or experience in your personal life that is related to the chapter(s).