3. PRECEDENT EVIDENCE
The act or event in which establishes
expectations for future conduct.
Two Forms
Legal Personal
4. LEGAL PRECEDENT
Most powerful and most difficult to
challenge.
Courts and legislatures
can establish legal
precedent.
Once a court makes a ruling, other
courts need to follow.
5. PERSONAL PRECEDENT
A result of watching the personal actions of
others to understand the expectations for future
behaviors.
Examples:
•Younger children in a family watch how
the older children are being treated in
order to see what precedents are being
established.
•The first month of marriage to establish
who precedent. Who cook, takes out the
garbage, cleans, etc.
Once established it is very
difficult to alter.
6. PRECEDENT AS EVIDENCE
The arguer refers to how the past event
relates to the current situation.
In legal situation In a personal situation
The argument is that the If you were allowed to stay
ruling in the current case out all night by your parents
should be the same as it “just once,” you an use that
was in the past, similar “just once” as precedent
situations. when asking that your
curfew be abolished.
7. STATISTICAL EVIDENCE
Consists primarily of polls, survey, and experimental
results from the laboratory. It provides evidence for
communicating a large number of specific instances
without citing each one.
“A person uses
statistics like a drunk
uses a lamppost, not
for illumination but
for support.”
-Great baseball announcer
Vin Scully
8. STATISTICAL AS EVIDENCE
Statistics are the product of a process subject to
human prejudice, bias, and error. Often no more
reliable than the other forms of evidence although
people often think they are.
Senders need to carefully
analyze how they use
statistics when attempting to
persuade others.
Receivers need to
question statistics that do
not make sense to them.
9. TESTIMONIAL EVIDENCE
Used for the purpose of assigning motives, assessing
responsibilities, and verifying actions for past, present
and future events. It is an opinion of reality as stated
be another person.
Three Forms
Eyewitness Historiography
Expert-witness
11. COMMON KNOWLEDGE EVIDENCE
A way to support one’s arguments. Most useful in
providing support arguments which lack any real
controversy.
No need for cite
opinions or survey
results to get most
people to accept a
statement. For
example, to get most
people to accept the
statement that millions
of people have seen
the show The
Simpsons.
