11' Multiple Causation and Interactions

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11. Multiple Causation and Interactions

• Stanovich
• Chapter 9

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• I expect to have marks ready within a week
• I will post marks on the course website.

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• Posted marks will include
• Student
• Unless you would prefer your grade not be listed
• MC total out of 40
• SA total out of 12
• Exam total out of 52
• Percent grade
• Scaled grade

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Grade Scaling

• As noted in the course syllabus, I am required to
  produce a class mean (average) of no higher than
  67
• If the class average is higher, grades will be
  scaled down
• If the class average is lower, grades will be
  scaled up

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Grade Distribution
67

• The Bell Curve

frequency
Grades
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How I Scale Grades

• First, I convert your grade to a z-score
• z (your grade) (class mean) / (class SD)
• Mean sum of all grades / N
• SD ?(X X)2
• Think of the SD as the average amount of
  variation in the grades

N 1
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• I then set the Mean and re-calculate your grade
  based on the new Mean
• Your new grade (z new Mean) ? SD

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Why not just add/subtract?

• Z-scores allow me to adjust the spread to the
  scores as well (the SD)
• Needed if scaling scores up resulted in someone
  being scaled higher than 100
• I can also adjust it to give a little extra help
  to keep someone from failing the course

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• Small vs. Big SD

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• The Dept prefers I scale grades for each
  exam/assignment, rather than at the end of the
  courseavoids surprises

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On to the lecture . . .

• You dont need to know about scaling techniques
  for final exam, its just so that you know what
  your marks are all about.

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Human Behaviour is Complex

• Most behaviours are the result of (caused by)
  many factors
• To say that A causes B, does not mean that A is
  the only thing that causes B

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Examples What causes . . .

• Crime?
• Poverty?
• Teen pregnancy?
• Relationship violence?
• (Your examples)

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Politics

• In Chapter 9, Stanovich goes on a bit of a rant,
  but the main point is that although the idea of
  multiple causes seems simple enough, when an
  issue becomes emotional/political, our
  explanations become increasingly singular.
• Most behaviours result from a variety of
  biological, dispositional, social and
  environmental factors.