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RESEARCH METHODS. Goals of Psychology. Describe - “what” Explain -“why” Predict -conditions under which a future behavior likely to occur Control - prevent unwanted behavior . Scientific Method.
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Goals of Psychology • Describe- “what” • Explain-“why” • Predict-conditions under which a future behavior likely to occur • Control- prevent unwanted behavior
Scientific Method Procedures that guide researchers in creating questions, generating evidence, and in drawing conclusions
Activity • All of us have the fundamental capacity to think and reason scientifically • So… • You are walking in the desert and find a man lying face down with a pack on his back, dead. How did he die? • Only ask me yes/no questions
Scientific Method • Foundation of scientific method- critical thinking • Objectively evaluating information to determine whether it follows logically from the evidence presented
Theory • Set of facts or relationship between facts that explains/predicts related phenomena • Tentative explanations • Reflects self-correcting nature of scientific method
Steps of the Scientific Method Formulate testable question-purpose Design study Analyze data Report results 7
Scientific Method-Step 1 • Formulate a testable question • hypothesis (proposed explanation for a situation)
Scientific Method-Step 2 3 ways to design studies: • Descriptive Method—describes behavior • Naturalistic observation • Case studies • Surveys • Correlational Method-how are variables related • Experimental Method—cause and effect relationship
Descriptive Design Naturalistic Observation Observe and record behavior as it occurs naturally Advantages: • detect patterns of behavior not likely to occur if subjects know being observed • can examine behavior that cannot ethically be examined in lab (bullying) • Generalize findings Disadvantage: observer bias
Descriptive Design Case Study • Single individual • Rare, unusual, or extreme conditions • Advantage: gain knowledge about rare cases • Disadvantage: findings cannot be generalized
Descriptive DesignSurvey Attitudes, opinions, beliefs of group -interviews -poll -questionnaire Advantages: • Quick • Inexpensive Disadvantage: • social desirability (people lie) • selecting representative sample
Surveys (cont’d) • Population— the complete collection; findings generalized to this group • Sample—subset of population • Representative sample—matches population on relevant characteristics (age, sex, education, income) that are in the same proportion as they are found in the population
Correlational Design Relationship between variables (how strongly/weakly are variables related?) • e.g., strong correlation between SAT scores and college GPA Advantages: • clarify relationships between variables • identify factors for further study • make meaningful predictions Disadvantages: • no causality • third variable problem
Correlation Coefficient Correlation coefficient – Strength and direction of the relationship between two variables -1.00 to +1.00 2 parts: number and sign - number indicates strength - sign indicates direction
Correlation Coefficient (cont’d) The closer the correlational coefficient is to 1.00 (+ or -), the stronger the correlation • Positive correlation—two variables vary systematically in the SAME direction (the more you study, the better your grades tend to be) • Negative correlation—two variables vary systematically in OPPOSITE directions (the more police on the street, the fewer crimes tend to occur) CORRELATION DOES NOT NECESSARILY INDICATE CAUSATION
Experimental Design • Only method that allows for causal determination • Variables-factors that are observed, measured, verified measured • Operational definition-precise description of variables
Experimental Design • independent variable: manipulated • dependent variable: measured • experimental group-receives treatment (IV) • control group-no treatment (used for comparison)
Experimental Method-Example • An investigator believed that children’s aggressive behavior will be increased by their observations of violence. To test his idea, he conducted an experiment. He showed films to two groups of children who were randomly assigned to two groups. One group viewed a segment of a very violent television program (“The Untouchables”). The other group viewed a program of a nonviolent athletic competition (a track event). Afterwards, he asked five graduate students (who were unaware of the design of his study or of which subjects were in which group) to observe and score instances of aggressive behavior in children from both groups playing together in a room. He found that children from the group who watched the “Untouchables” behaved significantly more aggressively than the children from the other group
Experimental Method Ex (cont’d) In this experiment: Hypothesis-watching TV violence can cause increase in aggression Independent variable- type of film (violent vs. nonviolent) Dependent variable-aggressive acts observed in children (subjects) Experimental group- group of children who watched “The Untouchables” Control group-group of children who watched track event
Experimental Design (cont’d) Advantages: • Precise control over variables • Causal determination Disadvantages: • highly controlled lab settings-not real • ethical considerations in creating more “real life” situations (I.e. prolonged exposure to noise on young children) • Researcher and participant bias
Types of Bias • Experimenter bias (demand characteristics)- subtle cues by the researcher - controlled by doubled-blind technique • Selection bias - how participants assigned to groups -controlled by random assignment Participant bias -participants mental expectations about treatment (participant exposed to placebo) - controlled by comparison to experimental group
Activity “I want to know…” • Identify what research method is the best way to answer the following research questions • Naturalistic observation • Case studies • Surveys • Correlational methods • Experimental
Scientific Method-Steps 3 & 4 • Step 3 - Analyze data to arrive at conclusions • Use of statistical procedures • Use of meta-analysis-analyzing the results of many research studies on a specific topic in order to identify overall trends • Step 4 - Report results • Publication • Replication
Ethical Guidelines • Informed consent and voluntary participation • Students as participants • Use of deception • Confidentiality of information • Information about the study and debriefing • Schacter's Affiliation Study - YouTube
Using Animals in Psychological Research • 90% of psychology research actually uses humans, not animals, as subjects • Many psychologists are interested in the study of animal behavior for its own sake (comparative psychology) • Animal subjects are sometimes used for research that could not feasibly be conducted on human subjects