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Research Methods: Psychology as a Science

Mr. Koch

AP Psychology

Andover High School

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Critical Thinking

  • Scientific attitude encourages

critical thinking

    • The process of assessing claims and

making judgments on the basis of

well-supported evidence

  • Examples of critical thinking questions:
    • What am I being asked to believe or accept?
    • What evidence is available to support the assertion?
    • Are there alternative ways of interpreting the evidence?
    • What additional evidence would help to evaluate the alternatives?
    • What conclusions are most reasonable?

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Research Techniques

  • Qualitative Measures
    • Uses descriptive (non-numerical) data, such as observations of behavior or personal accounts of experiences
      • Ex: structured interviews
  • Quantitative Measures
    • Measures variables using numerical data such as test scores or behavioral measurements
      • Ex: Likert scales

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Research Techniques

  • Survey
    • Gather data about or opinions from participants, usually through interview or self-report questionnaire
      • Who is included? Representative sample?
        • Random sample is usually best
      • Potential problems:
        • wording and clarity
        • self-report bias
        • social-desirability bias
        • data collection problems (nonresponse bias)

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Research Techniques

Longitudinal Study

  • Study same group of people over extended time period

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Cross-Sectional Study

  • Study people of different ages at same point in time

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Both are valuable for developmental studies

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RESEARCH METHODS

Experimental

Involves use of Independent Variable(s) and Random Assignment to groups

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(*we’ll examine this more later…*)

Non-Experimental

  • Naturalistic Observation
  • Case Study
  • Correlation
  • Meta-analysis

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VS.

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Research Methods

  • Naturalistic Observation
    • The process of watching without

interfering as behavior occurs in

the natural environment

      • Valuable when more intrusive measures might alter behavior
        • Ex: studying exercise, hand-washing
      • Can be distorted when people know they’re being watched and/or by observer’s expectations

(Hawthorne Effect)

      • Describes behavior, but doesn’t answer the “why”

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Research Methods

  • Case Study
    • Intense examinations of behavior/mental processes in a particular individual, group, situation – great “depth” of information
      • Useful when studying something new, complex, or rare
        • Ex: Oliver Sacks’ “Dr. P”
      • May not be representative

of general population

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Research Methods

  • Correlation
    • Scatter plot

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    • Correlation coefficient
      • r = +1.00 One set of scores goes up in direct proportion to the other

      • r = 0.00 Scores unrelated

      • r = -1.00 One set of scores goes up as the other goes down

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Correlation

  • + (positive)
    • Child abuse / aggressiveness
    • Education / income
    • Studying / grades

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  • - (negative)
    • Self esteem / depression
    • Age / hours of sleep
    • Stress / health

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  • “Illusory Correlations”:

A perceived correlation that really does not exist

(i.e. “lucky” penny, arthritis & weather, pregnancy cravings and sex of baby)

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  • Correlation DOES NOT prove causation
  • Only proves relationship, not cause and effect

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Correlation does not necessarily mean causation…

  • As ice cream sales increase, so does the number of shark attacks on swimmers.
          • “3rd variable problem” – both increase in summer
  • The greater the number of cavities in elementary school children, the greater the size of their vocabulary.
  • Research has shown the strongest correlation was between contraceptive use and number of electrical appliances in the home (Li, 1975).
  • Regions of Russia where there were many doctors had the highest rates of cholera among the peasantry.
  • A 1988 Harvard study showed that those students who took SAT “coaching” courses scored 63 points lower than those who did not.
  • There is a strong correlation between the number of churchgoers and the number of burglaries in a given town.

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Research Methods

  • Meta-analysis
    • A procedure for statistically combining the results of many different research studies
      • combines the effect size estimates from each study into a single estimate of the combined effect size
      • gives us the “bottom-line” results of many different studies

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