1. Psychology as a Science zIn this lecture we will discuss: yscience - a method for understanding ylimits of common sense ymethods of science xdescription xcorrelation xexperimentation yevaluating data with statistics ysources of error and bias in research

2. Science vs. Common Sense zCommon sense and intuition often tell us about psychology ye.g., suppose a study tells us that ‘separation weakens romantic attraction’ ycommon sense may tell us - “out of sight, out of mind” yor common sense may say the opposite - “absence makes the heart grow fonder” zCommon sense can be inconsistent and based on hindsight

3. Science vs. Common Sense zScience helps build explanations that are consistent and predictive rather than conflicting and postdictive (hindsight) zScience is based on yknowledge of facts ydeveloping theories ytesting hypotheses ypublic and repeatable procedures

4. Scientific Inquiry zFacts are what need to be explained yobjective - viewable by others ybased on direct observation yreasonable observers agree are true zTheory is a set of ideas that yexplains facts ymakes predictions about new facts zHypothesis yprediction about new facts ycan be verified or falsified

5. Methods in Psychology zSetting - field vs. laboratory zMethods of data collection yself-report vs. observational zResearch plan or design ydescriptive ycorrelational yexperimental

6. Descriptive Study zDescribes a set of facts zDoes not look for relationships between facts zDoes not predict what may influence the facts zMay or may not include numerical data zExample: measure the % of new students from out-of-state each year since 1980

7. Correlational Study zCollects a set of facts organized into two or more categories ymeasure parents disciplinary style ymeasure children’s behavior zExamine the relation between categories zCorrelation reveals relationships among facts ye.g., more democratic parents have children who behave better

8. Correlational Study zCorrelation cannot prove causation yDo democratic parents produce better behaved children? yDo better behaved children encourage parents to be democratic? zMay be an unmeasured common factor ye.g., good neighborhoods produce democratic adults and well behaved children

9. Experiments zDirect way to test a hypothesis about a cause-effect relationship between factors zFactors are called variables zOne variable is controlled by the experimenter ye.g., democratic vs. authoritarian classroom zThe other is observed and measured ye.g., cooperative behavior among students

10. Experimental Variables zIndependent variable ythe controlled factor in an experiment yhypothesized to cause an effect on another variable zDependent variable ythe measured facts yhypothesized to be affected

11. Independent Variable zMust have at least two levels ycategories - male vs. female ynumeric - ages 10, 12, 14 zSimplest is experimental vs. control yexperimental gets treatment ycontrol does not

12. Experimental Design zLevels may differ between or within people zWithin-subject experiment - different levels of the independent variable are applied to the same subject zBetween-groups experiment - different levels of the independent variable are applied to different groups of subjects

13. Experimental Design zRandom sample - every member of the population being studied should have an equal chance of being selected for the study zRandom assignment - every subject in the study should have an equal chance of being placed in either the experimental or control group zRandomization helps avoid false results

14. Research Settings zLaboratory ya setting designed for research yprovide uniform conditions for all subjects ypermits elimination of irrelevant factors ymay seem artificial zField research ybehavior observed in real-world setting ypoor control over conditions ymeasures may be more representative of reality

15. Data-Collection Methods zSelf-report - procedures in which people rate or describe their own behavior or mental state yquestionnaires yrating scales xon a scale from 1 to 7 rate your opinion of … yjudgements about perceptions xon a scale from 1 to 100 how hot is...

16. Data-Collection Methods zObservational methods - researchers directly observe and record behavior rather than relying on subject descriptions ynaturalistic observation - researcher records behavior as it occurs naturally ytests - researcher presents stimuli or problems and records responses