• Research in abnormal psychology is especially important: a wrong belief in the field leads to suffering

  • Schizophrenia: severe disorder that causes people to lose contact with reality

    • Lobotomies were believed to cure schizophrenia, but this was false

    • Wasn’t disproven until tens of thousands of people had been lobotomized

    • Caused irreversible brain damage that left patients withdrawn

What Do Clinical Researchers Do?

• Clinical Researchers / Clinical Scientists try to discover universal laws / principles of abnormal psychological functioning using the scientific method

• Clinical Practitioners assess, diagnose, and treat individual clients

  • seek an individualistic understanding of abnormal behavior

• Clinical Researchers use three methods of investigation to form hypotheses

  • Case Study: focused on one individual

  • Correlational and experimental methods

    • Observe many individuals

    • Apply procedures uniformly (allows for replication)

    • Use statistical tests to analyze results

The Case Study

• A detailed description of a person’s life and psychological problems

How Are Case Studies Helpful?

• Can be a source of new ideas about behavior

• Can challenge a theory’s assumptions

• Can show the value of new therapeutic techniques

• Can offer opportunities to study unusual problems

What Are the Limitations of Case Studies?

• Reported by biased observers

• Rely on subjective evidence

• Low internal and external validity scores

• Little basis for generalization

The Correlational Method

• Correlation: the degree to which events / characteristics vary with each other

• Correlational Method: research procedure used to determine correlation between variables

• Subjects / Participants: people chosen for a study

• Sample: collective name for participants in a sample

  • Must be representative of the larger population

Describing a Correlation

• Line of best fit

  • Positive Direction: when variables change the same way. shows positive correlation

  • Negative Direction: when variables change in different ways. shows negative correlation

  • Unrelated variables: there is no consistent relationship between variables and no slope

• Magnitude: How closely do the two variables correspond?

  • The closer the data points are to the line of best fit, the greater the magnitude between the variables

• Correlation Coefficient

  • Positive / negative sign of the coefficient signifies direction

  • The number represents its magnitude - the closer it is to zero, the lower the relationship the variables have

When Can Correlations Be Trusted?

• p < .05: Findings are statistically significant and are thought to reflect the larger population

• The larger the magnitude of the correlation and the bigger the sample ➝ the more likely it is that a correlation will be statistically significant

What Are the Merits of the Correlational Method?

• High external validity

• Lack internal validity - describes the relationship between two variables, but doesn’t explain it

  • Variables can be correlated for any reason

  • Correlation doesn’t equal causation

The Experimental Method

• Experiment: research procedure in which a variable is manipulated and the manipulation’s effect on another variable is observed

  • Independent variable

  • Dependent variable

  • Confounding variable

    • To guard against confounding variables, researchers should include a control group, random assignment, and a masked design

    • ex: bias

• Control Group: A group of research participants who are not exposed to the independent variable under investigation

• Experimental Group: The participants who are exposed to the independent variable

• Statistical Significance: Indicates whether a participant’s improvement in functioning occurred because of treatment

• Clinical Significance: Indicates whether the amount of improvement is meaningful in the person’s life

Random Assignment

• Random Assignment: Any selection procedure that ensures that every participant in the experiment is as likely to be placed in one group as the other

• Reduces the effects of preexisting differences

Masked / Blind Design

• Avoids bias in experiments

• Individuals are kept unaware of their assigned group

• Double-Masked Design: Prevents against both patient bias and experimenter bias

• Triple-Masked Design: Experimenters arrange for judges to assess and analyze the outcomes, and the judges are also kept unaware of group assignments

Alternative Research Designs

• aka Mixed Designs / Quasi-experimental Designs

• Designs that intermix elements of both correlational and experimental studies

Matched Designs

• Researchers match the experimental participants with control participants who are similar in age, sex, socioeconomic status, etc.

• Make use of groups that already exist in the world (ex: effects of abuse on children. splits children into groups of abused and not abused)

• Violates the rule of random assignment

• Matched design minimizes confounding variables caused by not using random assignment

Natural Experiments

• Nature itself manipulates the independent variable while the experimenter observes the effects

• Used for studying the psychological effects of natural disasters and other unpredictable events (floods, plane crashes, fires, etc)

Analogue Experiments

• Experimenters induce lab participants to behave in ways that seem to resemble real-life abnormal behavior

• Investigators can manipulate independent variables freely while avoiding ethical and practical limitations of clinical research

• Often use animals as participants

Single-Subject Experiments

• A single participant is observed both before and after the manipulation of an independent variable

• Rely on baseline data (information gathered before any manipulations) that can be compared to data gathered after the manipulation of an independent variable

Longitudinal Studies

• Researchers observe the same individuals on many occasions over a long period of time

Epidemiological Studies

• Determine the incidence and prevalence of a problem in a particular population

• Incidence: Number of new cases that emerge in a population during a given period of time

• Prevalence: Total number of cases in the population during a given period

  • Includes both existing and new cases

• Help researchers identify groups at risk for particular disorders

• Cannot confirm causation alone

Protecting Human Participants

• Institutional Review Boards: Committees of five or more members who review and monitor every study conducted at a research facility, starting at proposal

• Rules:

  • Participants enlist voluntarily

  • Before enlisting, the participants are given informed consent

  • The participants can end their participation at any time

  • The benefits of the study outweigh its risks

  • Participants are protected from physical and psychological harm

  • Participants have access to info about the study

  • Participants have protected privacy

• IRBs are flawed: Ethical principles can’t always be broken down into simple guidelines