Measurement

1
Measurement

• Types of Measures
• Levels of Measures
• Measurement Reliability
• Validity

2
Types of Measures (Scales)

• 1) Frequency counts (natural, absolute)
• 2) Established metrics (agreed upon units)
• 3) Measures of magnitude Typically multiple-item
  measures. (Often paper/pencil measures)
• Likert-style measures (a little a lot) (add
  items, sometimes reverse worded/scored)
• Semantic differential (opposites at each end)
• Guttman Scale (yes/no, items graded in intensity)

3
Likert-style measures

• I feel that I belong to this group.
• 1 2 3 4 5
  6
• Agree
  Disagree
• I am not like the other group members.
• 1 2 3 4 5
  6
• Agree
  Disagree

4
Likert type measuresSatisfaction with the
University

• . How satisfied are you with your Instructors?
• Very
  Very
• Dissatisfied
  Satisfied
• 1 2 3 4 5
  6 7
• How satisfied are you with your courses?
• 1 2 3 4 5
  6 7
• How satisfied are you with advising?
• 1 2 3 4 5
  6 7

5
Semantic Differential

• Please give your opinion of George Bush as a
  presidential candidate.
• Good ___ ___ ___ ___ ___ Bad
• Warm ___ ___ ___ ___ ___ Cold
• Dumb ___ ___ ___ ___ ___ Smart

6
Guttman Scale

• If you met someone on the bus and conversed with
  them, would you tell them each of the following?
• What you had for breakfast? ___
• Your pet peeves? ___
• Your biggest fear? ___

7
Levels of Measurement

• Nominal (categories that are a) mutually
  exclusive, b) exhaustive, c) equivalent Avoid
  nominal measure when possible
• Ordinal (rank ordered)
• Interval (equal numerical distances imply equal
  distances)
• Ratio (absolute 0)
• Measure variables as interval or ratio when
  possible

8
Levels of Measurement Examples

• Comforting Behavior (smile, hug, listen)
• Communication Apprehension (PRCA5 items)
  (Spielberger5 items)
• Valence (positive, neutral, negative)
• Vividness (little, moderate, considerable)
• Control (controlled, control not in evidence, in
  control)
• Reporter beats (crime, economic, political)

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Level of Measurement (cont)

• GPA A B C D E
• GPA _____
• Number of courses enrolled in_____
• Number of hours per week in class___

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Measurement Reliability

• Consistency
• A) Independent observers measuring the same
  concept should see the same thing. B) Independent
  instruments or measures should produce similar
  results.
• Reliability ranges from 0 to 1.0
• Acceptable reliability.80

11
Three Types of Reliability

• Test-retest reliability (stability)
• Internal (inter-item) reliability Cronbachs
  alpha. Typically used with interval level
  measures. (Communication Apprehension)
• Intercoder reliability (percent agreement)
  Typically used with nominal level measures (also
  in ordinal level valence, vividness, control)

12
Intercoder Reliability ExampleThemes from
Campaign Speeches

• Coder 1 Iraq
• Economy
• Homeland Security
• Education

• Coder 2
• Budget Deficit
• Economy
• Homeland Security
• Budget Deficit

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Validity

• Measurement validity
• Concurrent Validity
• Discriminant Validity