Chapter 2: The Research Enterprise in Psychology
The Scientific Approach to Behavior Basic assumption: –events are governed by some lawful order –Deterministic Viewpoint –Free Will cannot be studied scientifically
The Scientific Approach to Behavior Goals: –Measurement and Description Qualitative and Quantitative –Understanding and Prediction Theory Hypothesis –Application and Control Help improve people’s lives
Steps in a Scientific Investigation 1. Formulate a testable hypothesis –Operational Definition “Studying in a brightly colored room improves learning.” –Brightly Colored Room –Learning “People with a high self-esteem are more successful.” –High Self Esteem –Successful
Steps in a Scientific Investigation 2. Select the research method and design the study “Males are more aggressive than females.” Methods –Laboratory –Observations –Questionnaire –Evaluation of other data (courts, police records)
Steps in a Scientific Investigation 3. Collect the data –Recruit Sample –Conduct Study –Collect data
Steps in a Scientific Investigation 4. Analyze the data and draw conclusions –Use statistics –Was the hypothesis supported by the data?
Steps in a Scientific Investigation 5.Report the findings –Ensures accurate data –Check each other –Furthers research –Helps the profession
Types of Research Experimental Correlational Descriptive
Experimental Research Experiment = manipulates of one variable changes in a second variable –Type of research where the researcher manipulates of one variable under controlled conditions and observes changes in a second variable –Detection of cause-and-effect relationships
Experimental Research Independent variable (IV) = –The variable that is manipulated –The possible “cause” Dependent variable (DV) = –The variable that is measured –The “outcome or effect” Extraneous and confounding variables= –Any other variable affecting the outcome
Experimental and Control Groups Experimental group –Receives the special condition (the IV) Control group –Does not receive special condition Important –Random assignment –Manipulate IV for group only –Differences in the two groups must be due to the independent variable
Strengths and Weaknesses of Experimental Research Strengths: –conclusions about cause-and-effect can be drawn Weaknesses: –artificial nature of experiments –ethical and practical issues
Correlational Research Assesses the relationship between two variables. Cannot establish Cause and Effect
Correlation Correlation coefficient –+1.00 to –Direction of relationship (+/-) –Strength of relationship (#) Correlation and prediction
Figure 2.6 Positive and negative correlation
Descriptive Methods Methods used when a researcher cannot manipulate the variables under study –Naturalistic observation –Case studies –Surveys Allow researchers to describe patterns of behavior and discover links or associations between variables but cannot imply causation
Figure 2.10 Comparison of major research methods
Evaluating Research: Methodological Pitfalls Sampling Bias Placebo Effects Distortions in Self-Report Data: –Social desirability bias –Response set –Memory Experimenter Bias –the Double-Blind Solution Demand Characteristics
What’s Wrong A psychologist is conducting an experiment to determine whether exposure to pornography causes men to commit more sexual crimes. She randomly assigns 20 men to the experimental group, who watch a pornographic film, and 20 men to the control group, who watch an exciting, but not pornographic film, of the same length. After the film, she interviews the men and asks them whether they fell that they would be likely to commit a sex crime. The results show the more of the men who say the pornographic film say they would be likely to commit a sex crim.
Ethics in Psychological Research: Do the Ends Justify the Means? The question of deception The question of animal research –Controversy among psychologists and the public Ethical standards for research: the American Psychological Association –Ensures both human and animal subjects are treated with dignity
Figure 2.12 Ethics in research