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Thinking Critically with Psychology

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Research methods

Survey Case study

– E.g. Stroke victim

Experimentation Naturalistic Observation

– Observing behavior in a singles bar

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Comparing research methods

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How do you get people to study?

Population– All NSCC students

Representative Sample Random sample

– Ensures a representative sample

Random assignment

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Generalizing (Problems)

Generalizing from unrepresentative samples Generalizing from select cases

– Most remedial reading students in Mrs. Brown’s class are boys

– Therefore, boys have more trouble reading than girls

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Random sampling

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What do you study? - Variables

Variables Independent variable Dependent variable

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How are variables related? - Correlation Positive and negative

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Positive correlation

Mortality rates increase as people age Grades increase as study time increase

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Negative correlation

As income increases free time decreases As one goes up, the other goes down

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No Correlation

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Confusing correlation with causation “Correlation is not causation” Large brains (or ice cream) & violence

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Illusory correlation

Buying stocks that performed well last year Adoption and conception

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Hindsight bias

Explaining events in hindsight– Lee Harvey Oswald & Pres. Kennedy

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Perceiving order in random events Both have an equal chance of happening

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Perceiving order in random events (Cont.) Twins separated at birth having similar

interests, jobs, etc. Similarities between Lincoln and Kennedy.

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The experiment

Control Condition Placebo effect

– Placebo = Pill with no drug

The double blind procedure– Neither experimenter nor subject knows which

pill is the drug or placebo.