chapter 4

• Scientific Method


  Obtain and evaluate (in a systematic way) information that is relevant to a problem
• Operationalization


  The way we measure or manipulate the variables in a study
• Generalizability


  The ability to apply what we have learned to other individuals or groups
• Group comparison study


  A type of correlational study where researchers are interested in the relationship between people's membership in a particular group and their scores on some other variable
• Case Studies


  Detailed histories of unique individuals who have some form of psychological disorder
• Hypothesis


  A testable statement of what we predict will happen in a study
• DV


  The factor the study aims to predict
• IV


  The factor used or manipulated to predict the other variable
• Sample


  A group taken from the population of interest to participate in the study. The sample for the study must be representative of the population of interest, and the research must be generalizable to the population of interest
• Control Group


  A group similar in most ways to the primary group of interest but who do not experience the variable the theory hypothesizes causes changes in the dependent variable
• Third Variable


  Variables unrelated to the theory that still may have some effect on the dependent variable
• Basic Rights of the Participants

  • Understand the nature of the research they are participating in
  • Expect their identity and any information gathered from them to be held in strict confidence
  • Be allowed to refuse to participate or withdraw without adverse consequences
  • Informed consent to participate should be documented in writing
  • Not be defrauded about aspects that might affect willingness to participate
  • Be debriefed at the end of the study
• Correlational Studies


  Examine the relationship between two variables without manipulating the variables
• Correlation Coefficient


  An index of the relationship between two variables
• Positive Correlation


  Indicates that as values of one variable increase, values of the other variable increase
• Negative Correlation


  Indicates that as values of one variable increase, values of the other variable decrease
• Statistically significant


  A result that is unlikely to have happened by chance
• A correlational study can show that two variables are related, but it cannot show that one variable causes the other
• Third Variable Problem


  The possibility that variables not measured in the study actually account for the relationship between the variables measured in the study
• Continuous variable studies


  Evaluate the relationship between two variables that vary along a continuum
• Representative sample


  A sample that resembles the population of interest on all important variables. One way to generate this sample is to obtain a random sample
• Cross-sectional studies


  Assess a sample at one point in time
• Longitudinal studies


  Assess a sample at multiple points in time
• Double-blind Experiment


  Both the participants and the experimenters who interact with them should be unaware of whether participants are in the experimental condition or the control condition
• Internal Validity


  The extent to which changes in the dependent variable can confidently be attributed to our manipulation of the independent variable and not to other factors
• Demand Characteristics


  Situations that cause participants to guess the purpose of the study and thus change their behavior
• Wait list control groups

  Control participants wait to receive the interventions until after the studies are completed
• External Validity


  The extent to which a study's results can be generalized to real-life phenomena
• Group comparison studies


  Evaluate differences between key groups, such as a group that experienced a certain stressor and a matched comparison group that did not
• Epidemiological Studies


  Look at the frequency and distribution of a disorder in a population
• Prevalence


  The proportion of the population that has the disorder at a given point or period in time
• Incidence


  The number of new cases of the disorder that develop during a specific period of time
• Risk Factors


  Conditions or variables associated with a higher risk of having the disorder
• Experimental Studies


  Can provide evidence that a given variable causes psychopathology
• Therapy


  Outcome study allows researchers to test a hypothesis about the causes of a psychopathology while providing a service to participants
• Placebo control groups


  Participants receive the general support of therapists but none of the elements of the therapy thought to be active
• Single-case experimental designs


  Involve the intensive investigation of single individuals or small groups of individuals before and after a manipulation or intervention
• ABAB or reversal design


  An intervention is introduced, withdrawn, and then reinstated, and the behavior of a participant on and off the treatment is examined
• Multiple Baseline Designs


  An individual is given a treatment in different settings or multiple individuals are given a treatment at different times across different settings, and the effects of the treatment are systematically observed
• Animal studies raise questions about their generalizability to humans