Research in Abnormal PsychologyResearch in Abnormal PsychologyChallenges in Clinical ResearchWhat Do Clinical Researchers Do?Slide 5The Case StudySlide 7Slide 8Correlational & Experimental MethodsThe Correlational MethodSample Correlational Questions in Clinical ResearchDescribing a CorrelationPositive CorrelationNegative CorrelationNo CorrelationSlide 16Magnitude of CorrelationSlide 18When Can Correlations Be Trusted?What Are the Merits of the Correlational Method?Special Forms of Correlational ResearchThe Experimental MethodSample Causal Questions in Clinical ResearchSlide 241. The Control Group2. Random Assignment3. Blind DesignAlternative Experimental DesignsQuasi-Experimental DesignsNatural ExperimentsAnalogue ExperimentsSingle-Subject ExperimentsABAB (Reversal) DesignCase Study vs. Single-Subject DesignsPowerPoint PresentationResearch & Abnormal PsychologyResearch in Abnormal PsychologyChapter 29/5-9/8/14Research in Abnormal PsychologyResearch is the systematic search for facts through the use of careful observations and investigationsWhy is research important to abnormal psychology?Research allows us to evaluate theories and treatments for:1. Accuracy2. Effectiveness3. SafetyChallenges in Clinical Research•Clinical researchers face certain challenges that can make their work difficult:•Measuring unconscious motives•Assessing private thoughts•Monitoring mood changes•Calculating human potential•Clinical researchers must consider diverse features of the people they study, including cultural background, race, gender, sexual orientation, age, language of origin, etc. •They must always ensure that the rights of their research participants, both human and animal, are not violatedWhat Do Clinical Researchers Do?•Clinical researchers try to discover universal laws or principles of abnormal psychological functioning:•Nomothetic understanding•What really makes that person tick•Web that makes the whole person’s mind and thought processes•Researchers do NOT typically assess, diagnose, or treat individual clients •That is the job of clinical practitioners, who seek an idiographic, or individualistic, understanding of abnormal behaviorWhat Do Clinical Researchers Do?•Researchers rely on the scientific method•Three main methods of investigation:1.Case Study1. Case by case2. Focus on one person2.Correlational Design1. Correlation of two variables3.Experimental Design1. Results of manipulationThe Case StudyCase Study: A description of a person’s life and psychological problems: INDEPTH description of a single person’s life•Freud published many famous case studies•Dora•Rat Man•Anna O.•Showed that talk therapy is helpful•Just talking helps people relieve tension/anxietyThe Case StudyAdvantages:•Can be a source of new ideas about behavior•Freud’s theories based mainly on case studies•May offer tentative support for a theory•May challenge a theory’s assumptions•May show the value of new therapeutic techniques•May offer opportunities to study unusual problemsThe Case StudyLimitations•Is reported by biased observers•Relies on subjective evidence•Low internal validity•Provides little basis for generalization•Low external validityThese limitations are addressed by the two other methods of investigation…Correlational and Experimental MethodsCorrelational & Experimental Methods•Do not offer richness of detail, BUT•Do allow researchers to draw broad conclusions•Correlational and experimental methods are the preferred method of clinical investigation•Typically involve observing many individuals•Researchers apply procedures uniformly•Studies can be replicated•Researchers use statistical tests to analyze resultsThe Correlational Method•Correlation is the degree to which events or characteristics vary with each other•The correlational method is a research procedure used to determine the “co-relationship” between variables•The people chosen for a study are its subjects or participants, collectively called a sample•The sample must be representative of the larger populationSample Correlational Questions in Clinical Research•Are stress and onset of mental disorders related?•Is culture (or gender or race) generally linked to mental disorders?•Are income and mental disorders related?•Are social skills tied to mental disorders?•Is social support tied to mental disorders?•Are family conflict and mental disorders related?•Is treatment responsiveness tied to culture?•Which symptoms of a disorder disappear altogether?•How common is a disorder in a particular population?Describing a Correlation•Correlational data can be graphed and a “line of best fit” can be drawn•Direction of the correlation is important•Positive correlation (slope is upward and to the right): variables change in the same direction •Negative correlation (downward slope): variables change in the opposite direction •Unrelated (no slope): no consistent relationshipPositive CorrelationNegative CorrelationNo CorrelationDescribing a Correlation•The magnitude (strength) of a correlation is also important•High magnitude: variables which vary closely together•Strong relationship between variables•Data fall close to the line of best fit•Low magnitude: variables do not vary as closely together•Weaker relationship between variables•Data are loosely scattered around the line of best fitMagnitude of Correlation High Magnitude Lower MagnitudeDescribing a Correlation•Direction and magnitude of a correlation are often calculated numerically•This statistic is the correlation coefficient, symbolized by the letter r•The correlation coefficient can vary from +1.00 (perfect positive correlation) to -1.00 (perfect negative correlation)•Sign (+ or -) indicates direction•Number indicates magnitude•0.00 = no consistent relationship between variables•Most correlations found in psychological research fall far short of “perfect”When Can Correlations Be Trusted?•Correlations can be trusted if they are statistically significant•This is determined by a statistical analysis of probability•“Statistical significance” means that the finding is unlikely to have occurred by chance•By convention, if there is less than a 5% probability that findings are due to chance (p < .05), results are considered “statistically significant” and are thought to reflect the larger population•Generally, confidence