Chapter 2

• Research

  = the systematic search for facts through the use of careful observations and investigations
• What do clinical researchers/ clinical scientists do?

  • Discover universal laws and principles

  • Search for nomothetic understanding

  • Do not typically assess, diagnose, or treat individual clients

  • Rely on the scientific method
• scientific method

  = collecting & evaluating information through careful observations

  observations -> help explaining relationship between variables
• 3 main methods of investigation (used by clinical researchers)

  1. case study -> typically focused on one individual
  2. correlational method
  3. experimental method

  -> last two: used to gather info about many individuals
• hypothesis

  = A hunch or prediction that certain variables are related in certain ways

  -> tentative explanation offered to provide basis for an investigation
• nomothetic understanding

  = a general understanding of the nature, causes, and treatments of abnormal functioning, in the form of laws or principles
• case study

  = detailed description of a person's life & psychological problems

  -> describes person's history, present circumstances & symptoms
• Example of case study

  case study of Little Hans by Sigmund Freud

  -> 4yo boy who developed fear of horses
• case study

  = a detailed account of a person's life & psychological problems
• How are case studies helpful?

  • Detailed, interpretative description of a person's life and psychological problems

  • Source of new ideas about behavior

  • Tentative support for a theory

  • Challenge of a theory’s assumptions

  • Introduction of new therapeutic techniques

  • Opportunities to study unusual problems
• What are the limitations of case studies?

  • Biased observers -> bc therapists want to see their own treatment succeed

  • Subjective evidence (low internal validity)

  • Little basis for generalization (low external validity)
• internal validity

  = accuracy with which a study can pinpoint one factor as the cause of a phenomenon

  -> investigators are able to rule out all possible causes except one
• external validity

  = degree to which the results of a study may be generalized beyond that study
• correlation

  = The degree to which events or characteristics vary with each other

  • positive correlation: going up /
  • negative correlation: going down \
  • unrelated
• correlational method

  = research procedure used to determmine the co-relationship between variables
• subjects/ participants

  = ppl chosen for a study

  note: sample must be representative of the larger population
• negative correlation

  = value of one variable increases & value of other variable decreases
• positive correlation

  = variables change the same way
• unrelated variables

  = no consistent relationship between variables
• When can correlations be trusted?

  can be trusted based on a statistical analysis of probability

  -> ask how likely it is that study's findings have occured by chance; if chance is unlikely -> findings reflect real correlation in population

  • confidence increases with sample size & magnitude of correlation
• statistical significance

  = the finding is unlikely to have occured by chance
• Relative strengths & weaknesses of research methods

  :

  
• advantages of correlational method

  • high external validity (can generalize findings)
  • can repeat/ replicate studies with other samples
• difficulties with correlational studies

  • lack internal validity
  • describe but don't explain a relationship or causation
• epidemological study

  = A study that measures the incidence and prevalence of a disorder in a given population
• incidence

  = number of new cases that emerge during a given period of time
• prevalence

  = the total number of cases of a disorder occurring in a population over a specific period of time
• longitudinal study

  = A study that observes the same participants on many occasions over a long period of time
• experiment

  = variable is manipulated & the manipulation's effect on another variable is observed
• manipulated variable

  = independent variable
• variable being observed

  = dependent variable
• confound

  = variables other than the independent variable that may also be affecting the dependent variable
• control group

  = in experiment, group of participants who are not exposed to the independent variable, but whose experience is similar to that of the experimental group
• experimental group

  = in an experiment, the participants who are exposed to the independent variable under investigation
• statistical significance

  -> indicates whether a participant's improvement in functioning occured because of treatment
• clinical significance

  -> indicates whether the amount of improvement is meaningful in the individual's life
• 3 features to guard against confounds:

  • Control group

  • Random assignment

  • Masked (blind) design
• random assignment

  = any selection procedure that ensures that every participant in the experiment is as likely to be placed in one group as another
• Masked/ blind design

  = Experiment in which participants do not know which assigned group they are in
• placebo therapy

  = A pretend treatment that the participant in an experiment believes to be genuine