1. What is Evidence?
Nicole Codling
November 18, 2012
Speech 104

2. Meaning of Evidence
 In chapter 11of Communicating Critical Thinking,
it states that "evidence refers to specific
instances, statistics, and testimony, when they
support a claim in such a way as to cause the
decision maker(s) to grant adherence to that
claim.”
 According to Google dictionary, evidence is the
available body of facts or information indicating
whether a belief or proposition is true or valid.

3. Types of Evidence
 There are five different types of evidence:
 Precedent
 Statistical
 Testimonial
 Hearsay
 Common Knowledge
 Precedent Evidence – is an act or event that
establishes expectations for future conduct. There are
two different types of precedent evidence, personal
and legal.
 Personal Precedent Evidence is observational learning.
Take for example, one is learning to drive by watching a more
experienced driver. The driver sets the precedent for the
student driver by following or not following traffic laws.
 Legal Precedent Evidence are rulings that become legal
principle established by courts for future decisions.

4. Types of Evidence (cont.)
 Statistical Evidence – It is numerical reporting that primarily
comes from the results of polls, surveys, and scientific
experiments.
 Statistical evidence is not that reliable because the surveys can
be biased as well as the people that are chosen to take them.
 Testimonial Evidence – is an opinion of reality as stated by
another person. There are three forms of testimonial evidence:
 Eyewitness
 Expert-witness
 Historiography
 Eyewitness testimony – is a personal testimony. The person
was present at the time of the event and observed what took
place.
 Expert-witness – is a qualified person used to make a personal
declaration of the subject at hand. An expert witness can consist
of a psychologist, some type of scientist, etc.
 Historiography – is an historian (someone that “traces
influences, assigns motives, evaluates roles, allocates
responsibilities, and juxtaposes events in an attempt to
reconstruct the pass.”)

5. Types of Evidence (cont.)
 Hearsay Evidence – an assertion or set of
assertions widely repeated from person to
person, though its accuracy is unconfirmed by
firsthand observation. In simple terms, it is a
rumor. This type of evidence can only be effective
outside of a courtroom.
 Common Knowledge Evidence – is using one’s
knowledge as evidence to support an argument.
This type of evidence is usually used in an
argument that has no real controversy.

6. Why is Evidence Important to an
Argument ?
 Evidence is the foundation of an argument.
Without the facts that evidence provide, an
argument cannot prevail.
 As portrayed in the chapter 11 module, the
Greek pantheon structure breaks down what
each part of the structure represents:
 The roof = the claim
 The beams = the contentions
 The pillars = reasoning
 The foundation = the argument

7. Credibility of Evidence
 One needs to be able to tell others where you
obtained your evidence from. Not all evidence is
credible evidence.
 One can check the credibility of their evidence by
asking yourself the following questions:
 Specific Reference to Source – “ Does the advocate tell
you enough about the source that could easily find it
yourself?”
 Qualification of the Source – “Does the advocate give you
reason to believe that the source is competent and well
informed in the area in question?”
 Bias of the Source – “Could one easily predict the source’s
position merely from a knowledge of his/her job, his/her
political party, or organization he/she works for?”
 Factual Support – “Does the source offer factual support
for the position taken or simply state personal opinions as
fact?”

8. The Uses of Evidence
 Establish Conclusive Proof for Your Position –
“the use of evidence in such a way that the law
will not permit it to be contradicted, or that it is
strong and convincing enough to override any
objections to it.”
 Establish Circumstantial Proof for Your
Position – “various types of evidence are used to
form a link strong enough to prove one’s point.”

9. Testing Your Evidence
 One has to be able to trust the accuracy of it’s
evidence. There are a few tests that one can use to
check the accuracy of the evidence they have
acquired:
 Recency – How recent is the evidence that you are
using? Does the source have knowledge of a more
recent development?
 Sufficiency – “Is their enough evidence to justify all
of the claims being made from this source?”
 Logical Relevance – “Can one reasonably draw the
conclusion being urged based on what the evidence
states?”
 Internal Consistency – Does the source contradict
itself?
 External Consistency – “Are the claims by this

10. Evidence & Critical Thinking
 Throughout the course of this class, we were
being taught on how to become critical thinkers.
 A critical thinker is one who relies on reason
rather than emotions to make a decision or come
to a conclusion.
 Reason comes from evaluating facts (evidence).
 A critical thinker should be one whose mind can
be changed based on the evidence at hand,
putting aside one’s belief.

11. Works Cited
 Sterk, Jack and Jim Marteney. "Communicating
Critical Thinking." 2008. 167-174.