3Methods of Psychology: Scientific Method Science starts with an attitude and a desire for the truthSystematic empirical study of phenomena__________: keep the bias out, include all data and information even if it doesn’t “fit”__________: based on observable events__________: must be measurable
4Short Video What was the study? Did people believe it? What’s a placebo?Why do placebos work?
5Problems with Common Sense People see some parts of the world and miss othersdue to preconceptions, ability, attention, etc.)People notice those things that fit preconceptionsPeople often believe to be true whatever feels good
6The Scientific MethodTo develop theories about the world and to test those theories using observationsTheory: An explanationScientific theory is backed by dataThe scientific processIs self correcting (theories are tested, then revised, then tested)Theories are _________The process is objective and public
7The Science of Psychology Separating anecdotes, folk wisdom and advice from data and conclusions!Scientific Research is…Formulating _______________Testing __________ using the scientific methodInterpreting the resultsCommunicating the results --- realistically
8The goals of science Description: What happens? Prediction: When does it happen?Explanation: Why does it happen?TheoryCausal InferencesIntervention/Application: What could be done to help?These all build on each other
9Self Report Self-report methods: ask participants to tell you InterviewsQuestionnairesDaily diary methods
10Observational Data Observational Data Observations in natural settings Laboratory-based observation
11Research Designs Archival – digging through the vaults… Correlational research – when one goes up, what happens to the other?Longitudinal research – how do things relate over time?Experimental research – if one is changed, what happens to the other?
12Archival ResearchResearchers examine existing data that may or may not have been intended for researchHarker and Keltner (2001) used yearbook pictures to predict marital outcomes 30 years later
14Correlational Research Assess the naturally occurring associations among two variablesPositive correlationrewards are positively associated with satisfactionNegative correlationconflicts are negatively associated with satisfaction
15Correlational research The statistical concept of a “correlation coefficient (r)”Perfect positivecorrelation (+1.00)No relationship (0.00)Perfect negativecorrelation (-1.00)
16Correlation does not imply causation! Three possible interpretations of any correlation
17Pros and Cons of Correlational Research (descriptive) AdvantagesDisadvantages
18Longitudinal Research Data collected at 2 or more time pointsAssociations among variables across timeHow are feelings of love across time associated with divorce?
19Longitudinal Research Associations among variables within a dayHow does a partner’s behavior during the day influence feelings of commitment at night?
20Pros and Cons of Longitudinal AdvantagesDisadvantages
21Experimental Research Manipulate one variable to see if it causes changes in another variable.Does arousal lead to greater liking?AB
22Testing the WHATs and WHYs 1:1 correspondenceIf you pour x into y, you know x caused the explosionIf you pour x and z into y, you don’t know what caused the explosionRandom AssignmentIn large enough samples, characteristics will be equally distributed
23Experimental: Video Games & Violence What is an independent variable?What is a dependent variable?What is the point of experiments?What is random assignment?How are differences controlled?
24Pros and Cons of Experimental AdvantagesDisadvantages