Statistics

1
Statistics

• Statistics are numerical data.
• How were the instances collected?
• How representative was the sample (if any)?
• How reasonable is the generalization?
• How are the statistics interpreted?

2
Exercise A3

• Most (extent)
• Americans (population)
• favor U.S. involvement in the Middle East
  (property).
• A recent poll of 250 people living in or around
  Chicago (sample)
• revealed that 63 of those surveyed favor such
  involvement (finding).

3
Exercise A5

• In a recent, 40 (finding)
• Of the 2,000 men involved (sample)
• Reported at least minimal hair growth, and
  another 12 reported moderate hair growth
  (finding).
• These data clearly establish that Sibodil really
  (extent)
• Works to restore lost hair (property).
• (all men is the implied population.)

4
Exercise B

• 1. How was the sample chosen? How large was the
  sample?
• 3. Cant generalize from sample.
• 5. Small sample size. Is there any reason to
  generalize that the discontent is growing?

5
Exercise C

• 1. the last one. / The net effect
• 3. the past century. / These figures prove
• 5. the last quarter of 1999. / We have to
• 7. the last 300 years. / These statistics
• 9. proceed with executions. / Thus, capital
  punishment
• 11. June, July, August. / It certainly pays

6
Testimony

• Lay testimony Opinions of reliable observers
  with personal involvement.
• Expert testimony Knowledge and opinions arising
  from study or work experiences.
• Functions of testimony
• Verify truth or representative qualities of
  examples or statistics
• Explain reasoning
• Interpret data

7
Credibility of Sources

• Sufficient expertise
• Reasonable objectivity
• Access to information
• Accurate use of material
• Detail and clarity of evidence