Abnormal Psychology Chapter 2 Research in Abnormal Psychology Definitions Correlation Correlational Method Epidemiological Study Nomothetic Understanding a general understanding of the nature causes and the process of systematically gathering and evaluating Hypothesis Case Study a research procedure used to determine how much events the accuracy with which a study can pinpoint one of various the degree to which the results of a study may be generalized the degree to which events or characteristics vary along with each a hunch or prediction that certain variables are related in certain ways a detailed account of a person s life and psychological problems treatments of abnormal psychological functioning in the form of laws or principles Scientific Method information through careful observations to gain an understanding of a phenomenon Internal Validity possible factors as the cause of phenomenon External Validity beyond that study other or characteristics vary along with each other disorder in a given population Incidence specific period of time specific period of time occasions over a long period of time of the manipulation is observed Independent Variable determine whether it has an effect on another variable the independent variable is manipulated also acting on the dependent variable the independent variable in an experiment a variable other than the independent variable that is the number of new cases of a disorder occurring in a population over a the total number of cases of a disorder occurring in a population over a a research procedure in which a variable is manipulated and the effect in an experiment a group of participants who are not exposed to the variable in an experiment that is expected to change as a study that measures the incidence and prevalence of a a study that observes the same participants on many the variable in an experiment that is manipulated to Dependent Variable Longitudinal Study Control Group Experiment Prevalence Confound Blind Design Experimental Group Double Blind Design Random Assignment an experiment in which participants do not know whether they are in experimental procedure in which neither the participant nor a sham treatment that the participant in an experiment believes a selection procedure that ensure that participants are in an experiment the participants who are exposed to the independent variable under investigation randomly placed either in the control group or in the experimental group the experimental or the control condition Placebo Therapy to be genuine the experimenter knows whether the participant has received the experimental treatment or placebo experimental groups that already exist in the world at large Also called a mixed design manipulates an independent variable abnormal like behavior in laboratory participants and then conducts experiments on the participants Single Subject Experimental Design participant is observed and measured both before and after the manipulation of an independent variable an experiment in which investigators make use of control and a research method in which the experimenter produces an experiment in which nature rather than the experimenter a research method in which a single Analogue Experiment Natural Experiment Quasi Experiment o researchers use the scientific method to uncover nomothetic characteristics of abnormal psychology o 3 methods used to examine relationships between variables Key Concepts What Do Clinical Researchers Do 1 case study 2 correlational method 3 experimental method Case Study o detailed account of a person s life psychological problems o purposes i source of ideas about behavior ii iii iv v support for theories challenges existing theories clarifies new treatment techniques offers as an opportunity to study rare cases o downfalls i ii iii observer bias relies on subjective evidence low internal external validity Correlational Method o systematic observation of the degree to which events or characteristics vary o allows researchers to draw broad conclusions about abnormality in the population together at large o correlation may have a POSITIVE or NEGATIVE DIRECTION o correlation may be HIGH or LOW in MAGNITUDE o correlational coefficient r o p 05 correlation is considered statistically significant o high external validity o low internal validity o two widely used forms 1 epidemiological studies goal DESCRIBE the incidence or prevalence of a disorder within groups or populations without trying to predict or explain why it occurs longitudinal studies 2 goal observe the same participants over a long period of time Experimental Method o researchers manipulate suspected causes to see whether expected effects will result o aspects of an experiment independent variable dependent variable control group experimental group random assignment confounds blind designs i ii iii iv v vi vii Alternative Experimental Designs o quasi experimental design groups may be unethical example effects of child abuse use of groups that already exist because making control and experimental children who have been abused group 1 i ii matched control participants group 2 children of the same age sex race etc as those in group 1 o natural experiments nature itself manipulates the independent variable example participants who have just experienced a natural disaster vs participants of neighboring cities who were not affected matched control participants o analogue experiments often use animals as participants induce laboratory participants to behave in ways that seem to resemble real life abnormal behavior example depression feeling of loss of control over one s life laboratory participants subjected to loud noises and shocks emotions are monitored o single subject experiment i ii rare disorders few participants ABAB design subject is its own comparison group i ii iii iv v vi baseline period application removal of independent variable IV participant is exposed to the variable and then it is removed for researchers to compare the subject s behavior IV applied condition A IV removed condition B IV applied condition A again IV removed condition B again