Listening and critical thinking 5.4 83
presented to support a case.^25 Without credible supporting evidence, it would
not be wise to agree with a speaker’s conclusion.
What should you listen for when trying to decide whether evidence is cred-
ible? If, for example, a speaker says, “It’s a fact that this herbal weight-loss pill
helps people lose weight,” your job as a listener is to determine whether that
statement is actually a fact. Has it been proven with direct observation to be
true? The speaker has an obligation to provide evidence to support the state-
ment that has been asserted.
Some speakers will support a conclusion with examples. But if the exam-
ples aren’t typical, if only one or two examples are offered, or if other known
examples differ from the one the speaker is using, then you should question the
conclusion.
Another form of evidence that a speaker might use to convince you is an
opinion. Simply stated, an opinion is a quoted comment from someone. The best
opinions come from reliable, credible sources. What makes a source credible?
A credible source is someone who has the credentials, experience, and skill to
make an observation about the topic at hand. Listen for the source a speaker
cites when quoting an expert on a subject.
A fourth kind of evidence that is often used, especially with a skepti-
cal listener, is statistics. A statistic is a number that summarizes a collection of
examples. Some of the same kinds of questions that should be raised about other
forms of evidence should be raised about statistics: Are the statistics reliable,
unbiased, recent, representative, and valid?
Here, we have introduced you to the importance of listening for good evi-
dence. Because evidence is an important element of public speaking, we’ll pro-
vide more detailed information about how to use evidence when we discuss
using supporting material in Chapter 8 and using evidence to persuade in Chap-
ters 16 and 17.Evaluate the Underlying Logic and Reasoning
An effective critical listener listens not only for evidence but also for the overall
structure of the logic, or argument, a speaker uses to reach a conclusion. Logic
is a formal system of rules applied to reach a rational conclusion. A speaker is
logical if he or she offers appropriate evidence to reach a valid, well-reasoned
conclusion. For example, Angela tried to convince her listeners to take the
weight-loss herb Slimlean by pointing out that many stores sell this diet prod-
uct, but that is not a strong logical framework for her conclusion. Just because
Slimlean is readily available does not mean that it’s effective and safe.
Reasoning is the process of drawing a conclusion from evidence within the
logical framework of the arguments. Can we reasonably conclude that anyone
can lose weight by taking Slimlean simply because the product is available in
many stores? The evidence very likely does not support this conclusion. When
a speaker is seeking to change your behavior, listen especially carefully to theM05_BEEB3981_05_SE_C05_065-094.indd 83 07/11/14 11:45 AM