Scientific Method - Abnormal Psychology - Lecture Slides, Slides of Abnormal Psychology

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The Scientific Method in

Abnormal Psychology

The Scientific Method in Clinical Research

• Replication: Results must be repeated in multiple studies to lessen the chance of findings due to experimenter bias, methodological flaws, or sampling errors.
• Scientific Method: Provides systematic collection of data through controlled observation.

Characteristics of Clinical Research

• Statistical vs. clinical significance:
  • Statistical Significance: The likelihood that a relationship could be due to chance alone. - Remember, in science we cannot “prove” anything, just be pretty sure. - Statistical significance refers to how “sure” we are that something is true.
  • Clinical Significance: Whether a statistically significant finding has any practical relevance in a clinical setting.

Research Methods Used to Study Psychopathology

• Experiments
  • Experimental hypothesis: Prediction concerning how an independent variable (possible cause) affects a dependent variable (factor acted on).
  • Does X (Independent Variable) cause Y (Dependent Variable)?
• Eliminating extraneous (confounding) variables promotes internal validity. - External Validity: Findings can generalize to other groups or conditions. - Internal Validity: Said to be high if the results of a study are due only to those factors included in the research investigation. docsity.com

Experiments

• Additional Concerns in Clinical Research:
  • Placebo group can also report significant improvements
  • Participants may “guess” correctly that they are receiving placebo treatment, thereby reducing expectancy effects
  • Experimenter or participant expectations can also influence outcomes of studies

Correlational Research

• Correlation: Extent to which change in one variable is accompanied by change in second variable.
• Variables are not manipulated
• Is increase in one variable accompanied by increase or decrease in another variable?

Correlational Research

• Correlation Coefficient ( r ): Expresses relationship between variables (value between – 1 and +1)
• Shows degree of relationship, not the reason for the relationship

Other Research Methods for Studying Abnormal Behavior

• Analogue Studies: Replicate or simulate real-life situation under controlled conditions. - Simulating the effects of stress on the release of cortisol using rats.
• Field Studies: Behaviors and events observed and recorded in their natural environment. - Higher external validity

Other Research Methods for Studying Abnormal Behavior

• Single-Participant Studies:
  • Case study: Intensive study of one individual
  • Single-participant experiment: Some aspect of a person’s behavior is used as a control/baseline for comparison with future behaviors. - Measure symptoms, introduce treatment and measure symptoms again, remove treatment and measure symptoms again.

Other Concepts in Biological Research

• Iatrogenic Effects: Unintended effects of therapy (side effects) - Recovered memories produced by hypnosis?
• Penetrance: Degree to which a genetic characteristic is manifested by individuals carrying specific genes associated with it. - Relationship between genotype and phenotype

Other Research Methods for Studying Abnormal Behavior

• Some information-producing strategies:
  • Survey research
    • Careful your sample is representative!
    • Dewey vs. Truman
  • Longitudinal research
    • To study affects of a disorder over time
  • Twin studies
    • Help sort out nature/nurture questions
  • Program evaluation
    • Analyze effectiveness of interventions

Epidemiological Research

• Epidemiological Research: Examines the rate and distribution of mental disorders in the population. - Prevalence Rates: Percentage of individuals in targeted population with a particular disorder during a specific period of time. - Incidence Rate: Onset or occurrence, number of new cases of a disorder in an identified population within a specific period of time.