Evidence

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Evidence
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Evidence

• Evidence supporting material known or
  discovered, but not created by the advocate.
  (Wilbanks, Church)
• The minor premise of the classical logical model
• The grounds or data of the Toulmin model

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Forms of Evidence

• Facts descriptions of events, objects, persons,
  or places which are empirically verifiable
  (Wilbanks and Church)
• Empirically verifiable means they could be
  confirmed through observation.
• Observation could be through looking, measuring
  or using scientific instruments to observe
  something.
• This also means it is repeatable in
  experimentation.

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Forms of Evidence

• Statistics A particular kind of factual
  evidence, which consists of quantified
  descriptions of events, objects, persons, places
  or other phenomena. (Wilbanks and Church)
• How much, how big, how many, how often, etc
• Can indicate relationships, trends and changes.

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Joel Bests guide for statistics

• Good statistics are based on more than guessing
• Good statistics are based on clear, reasonable
  definitions.
• Good statistics are based on clear, reasonable
  measures.
• Good statistics are based on good samples.

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Forms of evidence

• Examples descriptions of individual events,
  objects, persons, or places (Wilbanks and Church)
• Hypothetical examples should not be used as
  evidence to support a claim
• Literal examples should be used instead events
  that really happened, and can be in the form of
  brief stories.

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Forms of evidence

• Testimony authoritative opinion evidence that
  interprets or judges events, objects, persons, or
  places (Wilbanks and Church)
• Expert testimony is best coming from someone
  who is an expert in the field
• Can be in quotations or paraphrased
• Interpretive testimony evidence that describes,
  analyzes or explains and object, event, person or
  place (Wilbanks and Church)
• Judgment testimony presents a determination of
  the value of the event, person, object or place

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Classifications of evidence

• Higher quality evidence makes a stronger argument
• Primary evidence vs. Secondary Evidence
• Primary evidence comes from the source closest
  to its actual happening, and a source with first
  hand information
• Secondary evidence comes from a source at least
  one step away from the actual happening, with
  secondhand information
• A newspaper who reports on a research finding is
  a secondary source

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Expert vs. Lay evidence

• Expert evidence comes from a source who is
  experienced and knowledgeable in a subject
• Lay evidence comes from a source who is neither
  experienced nor knowledgeable in the area of
  discussion

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Casual vs. Created Evidence

• Casual evidence is evidence that naturally occurs
  without anyone trying to create it as evidence.
  Ex. Fossils, geography
• Created evidence is something purposely recorded
  for future use.
• Ex. Photos, medical records, grades
• This type of evidence depends on the
  circumstances for judgment.

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Six Tests of Evidence

• Source Credibility examines whether the source
  of the information has background, knowledge,
  expertise, and opportunity to be relied on.
• Source evidence can be a person or an
  organization
• Source can be primary or secondary
• Source can be expert or lay
• Also needed for credibility is trustworthiness

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Source bias

• Whether the source of evidence has any
  self-interests that could distort perception or
  reports.
• Does the bias affect the value of the evidence
  you get from the source?
• Does the source profit or personally gain from
  others accepting a particular viewpoint?
• Is there a cultural bias?

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Recency

• Considers whether the evidence came from an
  appropriate time period for the conclusion.
• In most cases, recent information is better than
  old information.
• Newer evidence is able to build on older
  evidence, extending and improving it.
• It can also correct mistakes of older evidence.
• Older evidence is good if it is a primary source,
  ex. Historical documents

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Internal Consistency

• There are no overt or subtle contradictions in
  the source of evidence.
• In other words, the source doesnt say one thing
  in one place, and something else in another.
• Examples inconsistencies (flip-floppers) in
  political campaigns

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Completeness

• Does the evidence provide enough information for
  a critical thinker to accept?
• The more complete the evidence the stronger the
  argument.
• Example scientist explains how data was
  gathered, how experiment was done in detail
• Completeness includes citing where the
  information came from in detail and the
  qualifications of the source

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Corroboration

• Also referred to as external consistency
• Corroboration asks whether other qualified
  sources agree with this source of evidence.
• Such consensus among qualified people provides a
  reason to have more faith in what the source
  says.
• Example Movie advertisers quote praise from
  several critics.

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Perellas Heirarchy of Evidence

• Level 1 assertion - The arguer says that some
  evidence is true without any verification.
• Level 2 Judicial notice / common knowledge
  when all parties agree to a fact, so there is no
  need to provide testimony to support it.
• Level 3 Lay opinion reasoned opinion by those
  people outside an area of expertise
• Level 4 Expert opinion / Consensus of Lay
  opinion the reasoned opinion of someone about a
  subject within their field of expertise.

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More

• Level 5 Empirical study / consensus of Expert
  opinion
• Empirical study well designed observational
  research. Such as a scientific experiment, a
  survey, or some other observable data.
• Consensus of Expert opinion the agreement of
  people who are experts in their field
• Level 6 Consensus of studies When there is
  agreement amongst several well designed research
  studies.

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Citations

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