Basic Components of Research

• Starts with a hypothesis or “educated guess”

  • Not all hypotheses are testable

  • Hypotheses in science are formulated so that they are testable

• Research Design: a method to test hypotheses

  • Independent variable: the variable that causes or influences behavior

  • Dependent variable: the behavior influenced by the independent variable

Considerations in Research Design

• Internal validity vs. external validity

  • Internal validity: extent to which results of a study are due to the independent variable

  • External validity: extent to which results of a study are generalizable to the population it’s studying

• Ways to increase internal validity by minimizing confounds

  • Use of control groups

  • Use of random assignment procedures

  • Use of analogue models

Statistical vs Clinical Significance

• Statistical methods – branch of mathematics

  • Helps to protect against biases in evaluating data

• Statistical vs. clinical significance

  • Statistical significance – asks are results due to chance?

  • Clinical significance – asks are results clinically meaningful?

  • Statistical significance does not imply clinical meaningfulness

• Balancing statistical versus clinical significance

  • Evaluate effect size

  • Evaluate social validity

Studying Individual Cases

• Case study method

  • Extensive observation and detailed description of a single client

  • Foundation of early historic developments in psychopathology

• Limitations

  • Lacks scientific rigor and suitable controls

  • Internal validity is typically weak

  • Often entails numerous confounds

Research by Correlation

• Correlation: assess the degree to which levels of certain variables are linked to levels of other variables

• The nature of correlation

  • Statistical relation between two or more variables

  • No independent variable is manipulated

  • Range from –1.0 to 0 to +1.0

  • Negative vs. positive correlation

• Necessary in situations where you can’t manipulate variables

• Limitations

  • Does not imply causation

  • Problem of directionality

Epidemiological Research

• An example of the correlational method

• Surveys large groups of people to get a picture of an entire population

• Examines incidence, prevalence, and course of disorders

  • Examples – AIDS, trauma following disaster

Research by Experiment

• Nature of experimental research

  • Manipulate independent variable

  • Observe effects on dependent variable

  • Attempt to determine causal relationships

  • Premium on internal validity

• Group Experimental Designs

  • Involves manipulating a variable (i.e., introducing or withdrawing something in a controlled way)

  • Clinical trial: experiment designed to evaluate the effectiveness of a treatment

  • Example: Administering a drug

Control Groups in Clinical Trials

• Control group: provides a comparison point

  • Often matched to demographics of experimental group

  • Placebo: some participants are given an inactive treatment (e.g., sugar pill), but participants don’t know which treatment they are getting

  • Double-blind: participants and assessors are unaware of what kind of treatment participants are getting

• Placebo effect: something changes simply because the participant expects the change to occur (e.g., expecting to feel better when taking an inactive pill)

Single-Case Experimental Designs

• Nature of single subject design

  • Rigorous study of single cases

  • Manipulate timing and nature of experimental conditions

  • Frequent repeated measurement of outcomes is critical

    • Permits conclusions about changes over time relative to the introduction and withdrawal of certain variables

• Types of single-subject design

  • Withdrawal designs

    • First establish a baseline, then introduce treatment

    • Then, stop treatment to see if behavior/symptoms return to the way they were before treatment

    • May present ethical concerns if an efficacious treatment is removed

  • Multiple baseline designs

    • Start treatment at different times in different conditions (e.g., in home vs. school settings) – see if changes occur in conjunction with introduction of treatment

    • Improves internal validity

Studying Genetics

• Behavioral genetics

  • Interactions of genes, experience, and behavior

  • Phenotype vs. genotype

    • Genotype: genetic makeup

    • Phenotype: observable characteristics (e.g., eye color, degree of shyness)

  • Endophenotype: genetic mechanism that contributes to problems causing certain symptoms

    • Example: Group of genes responsible for impairing working memory in schizophrenia

• Family Studies

  • Proband: The person who has the trait of interest (e.g. someone who has schizophrenia)

  • If there is a genetic influence, expect to see the trait more in first-degree relatives compared to second-degree

  • Familial aggregation: tendency of a disorder to run in families

  • Issue of shared environment: families usually live together, so similarities may be due to environmental factors as well as genetics

• Adoption studies

  • One way to separate the effects of the environment

  • Sibling pairs separated after birth: Do they show similarities even if they were raised in different environments?

  • Are adopted children more similar to their birth parents (genetics) or adoptive parents (environment)?

• Twin studies

  • Compare identical/monozygotic twins against fraternal/dizygotic twins

  • If a trait is genetic, expect to see greater concordance in identical twins (similar environment and same genetics) compared to fraternal twins (similar environment, different genetics)

  • Can be combined with adoption studies: If identical twins are both adopted separately and raised apart, shared outcomes are more attributable to genetics

• Genetic linkage studies and association studies

  • Examine known genetic markers (certain gene whose location is known)

  • Compare these genetic markers against the trait being studied

  • If the genetic marker tends to co-occur with the trait, conclude that the trait is probably caused in part by genes that are in close proximity to the genetic marker (e.g. on the same chromosome)

  • Genetic linkage studies occur in groups of people who all have the trait of interest

  • Association studies occur in people with and without the trait of interest

Studying Behavior Over Time

• Prevention research

  • Health promotion: increasing healthy behavior in entire population (even people not at risk for developing disorders)

  • Universal prevention: target specific risk factors but not specific people

  • Selective prevention: targets groups of people at risk

  • Indicated prevention: targets specific individuals who are showing early signs of a disorder

• Time-based research strategies

  • Cross-sectional designs: take a cross section of the population at different age groups

    • Compare cohorts (age groups) on traits of interest

• Longitudinal designs: study one group of people over time

  • Have to take into account specific experiences of the generation being studied (cross- generational effect)

Studying Behavior Across Cultures

• Value of cross-cultural research

  • Overcoming ethnocentric views

  • Increases understanding of

    • Etiologies

    • Symptom presentations

    • Treatments

• Difficulties in cross-cultural research

  • Definitions of abnormal behavior

  • Variance in presentation

  • Availability of valid assessment instruments may be limited

Research Programs

• Components of a research program

  • Set of interrelated research questions

  • Draw on several methodologies in finding answers

  • Conducted in stages, often involving replication

• Allows for more nuanced, complete picture of a phenomenon

• Replication is critical

  • Protects against fluke results

Research Ethics

• Sometimes, needs of science (e.g., designing a good experiment) are at odds with needs of research participants (e.g., need for treatment)

  • Research ethics determine the degree to which each should be prioritized

• Ethic determined by institutional review boards (IRBs) and the APA ethics code

  • Oversee the rights of human subjects participating in research

  • Maje sure research and data are handled responsibly

• Ethical principals

  • Informed consent

    • Became more widely discussed after Nazis had forced people to participate in research in WWII

  • Competence: ability to provide consent

  • Voluntarism: lack of coercion

  • Full information: necessary information to make an informed decision

  • Comprehension: understanding about benefits and risks of participation