Unit 2 (B): Non-Experimental Research Designs

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Unit 2 (B)Non-Experimental Research Designs

• Mr. McCormick
• A.P. Psychology

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Do-Now(In Journal)

• Think of a psychological phenomenon that you
  would be interested to research (a behavior,
  habit, disorder, etc.)
• Briefly describe how you could hypothetically
  carry out your research

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Pre-Research Decisions

• Population
• All the cases in a group being studied, from
  which samples may be drawn
• E.g. The entire CHS student body (2,000 students)
• Sample
• Small group of participants, out of a total
  population, that a researcher studies
• Representative vs. Non-representative
• E.g. 200 CHS students

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Pre-Research Decisions

• What might a representative sample of CHS
  students look like?
• How could we effectively get a representative
  sample of CHS students?

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Pre-Research Decisions

• Random Sample
• A sample that fairly represents a population
  because each member has an equal chance of
  inclusion

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Non-ExperimentalResearch Designs

• Naturalistic Observation
• Observation of subject(s) in a natural setting
  without manipulating or controlling the situation
  (e.g. watching teenagers in a mall)
• Case Study
• Intensive investigation of participant(s) (e.g.
  long-term interviews, living with participants,
  journals, video blogs)
• Survey
• Information is obtained by asking many
  individuals a fixed set of questions (e.g.
  questionnaire on self-reported attitudes or
  behaviors)

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Non-ExperimentalResearch Designs

• Longitudinal Study
• Studying a group of participants over a number of
  years (e.g. following a group of high school
  freshmen throughout their high school career)
• Cross-Sectional Study
• Studying groups of participants of different ages
  and comparing them to draw conclusions about age
  (e.g. studying a group of freshmen and seniors)

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Non-ExperimentalResearch Designs

• Think of an example in which each of the
  following research designs would be most
  effective
• Naturalistic Observation
• Case Study
• Survey
• Longitudinal Study
• Cross-Sectional Study

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Correlation

• Correlation
• A measure of the extent to which two factors vary
  together (and how well one factor predicts the
  other)
• Does not demonstrate causation
• Can be positive or negative
• Can be illusory (appears to be relationship where
  none exists)
• Measured with scatterplots
• Measured by a correlation coefficient r (-1 to
  1)

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Correlation

• What naturally-existing correlations
• can you think of?

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Correlation

• Positive Correlation
• Direct relationship
• Both factors increase together Both factors
  decrease together
• E.g. Amount of sleep and GPA
• Right Perfect Positive Correlation (r1.00)

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Height and Temperament in Men
r0.63
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Correlation

• Negative Correlation
• Inverse relationship
• One factor increases, while the other decreases
• E.g. Physical exercise and fat content
• Right Perfect Negative Correlation (r-1.00)

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Correlation

• What do you think a scatterplot would look like
  for two factors that are not correlated?
• What would its correlation coefficient be?
• r0.00

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Correlation ? Causation
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Review

• What is the difference between a population and a
  sample?
• How could one effectively create a representative
  sample?
• What is the difference between a positive and
  negative correlation?
• What are some implications of a correlation?

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Homework

• Research Study Response 40 Obey At Any Cost?
  (Pgs. 308-317)