research designs. agenda experimental designs natural experiments time series and panel designs...
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AgendaAgenda
Experimental DesignsExperimental Designs
Natural ExperimentsNatural Experiments
Time Series and Panel DesignsTime Series and Panel Designs
Cross Sectional DesignsCross Sectional Designs SurveysSurveys
AnnouncementsAnnouncements
Next week- half of you meet in library Next week- half of you meet in library Tuesday, half come here, flip for ThursdayTuesday, half come here, flip for Thursday
A through McGrath meet in Library A through McGrath meet in Library Tuesday, Here ThursdayTuesday, Here Thursday
Mickelson-Z meet here Tuesday, Library Mickelson-Z meet here Tuesday, Library ThursdayThursday
Don’t read Johnson 6, 11Don’t read Johnson 6, 11
RecapRecap
HypothesesHypotheses
VariablesVariables
Units of AnalysisUnits of Analysis
Positive, negative, spurious, Positive, negative, spurious, antecedent/intervening/mediating, antecedent/intervening/mediating, moderatingmoderating
Intro to Iyengar and KinderIntro to Iyengar and Kinder
Media and Public Opinion: Hypodermic Media and Public Opinion: Hypodermic Needles to Minimal Effects to ??Needles to Minimal Effects to ??
How might you study media effectsHow might you study media effects
Why might experiments be useful?Why might experiments be useful?
ExperimentExperiment
Allows for the greatest level of researcher Allows for the greatest level of researcher controlcontrol
Systematically vary one variable at a timeSystematically vary one variable at a time
Control GroupControl Group
Treatment GroupTreatment Group
Stimulus/TreatmentStimulus/Treatment
ExperimentExperiment
AssignmentAssignment MatchingMatching RandomRandom
Within Subjects DesignWithin Subjects Design
Between Subjects DesignBetween Subjects Design
Classic ExperimentClassic Experiment
Randomly assign groupsRandomly assign groups
Test at time 1Test at time 1
Provide treatment to one groupProvide treatment to one group
Provide no treatment to other groupProvide no treatment to other group
Test at time 2Test at time 2
Both between and within subjects designBoth between and within subjects design
Iyengar and KinderIyengar and Kinder
Hypotheses- MultipleHypotheses- Multiple Exposure influences agendaExposure influences agenda Exposure influences accountabilityExposure influences accountability Qualities of story matterQualities of story matter
Recruit a random sample of citizensRecruit a random sample of citizens
Participants watch the newsParticipants watch the news
Mild deception- watch with us to avoid Mild deception- watch with us to avoid distractionsdistractions
Iyengar and KinderIyengar and Kinder
PretestPretest
What are key IVs/DVs?What are key IVs/DVs?
Show TV newsShow TV news Control group- Unaltered NewsControl group- Unaltered News Treatment group- Added StoryTreatment group- Added Story
Post Test measuresPost Test measures
Findings- Agenda Setting and Priming on Findings- Agenda Setting and Priming on Most issuesMost issues
Iyengar and KinderIyengar and Kinder
Interesting Features?Interesting Features?
Create natural environmentCreate natural environment
Tight Control of StimulusTight Control of Stimulus
Number of ConditionsNumber of Conditions
No pre testNo pre test
Is it desirable to pretest?Is it desirable to pretest?
Between Subjects TestBetween Subjects Test
Example- Druckman and Holmes 2005Example- Druckman and Holmes 2005
Comparison between groupsComparison between groups
Random Assignment makes comparison Random Assignment makes comparison validvalid
Quasi Experimental ApproachesQuasi Experimental Approaches
Increased control over non experimental Increased control over non experimental techniquestechniques
Less control than true experimentLess control than true experiment
Sidanius and PrattoSidanius and Pratto
Social Dominance TheorySocial Dominance TheorySecret Shopper ParadigmSecret Shopper ParadigmSend different races, genders to do various Send different races, genders to do various taskstasksLook at and bargain for apartmentLook at and bargain for apartmentBargain for carBargain for carApply for jobApply for jobControlsControlsResults- White men do best, African-American Results- White men do best, African-American Men do worstMen do worst
Natural ExperimentsNatural Experiments
Two similarly matched entitiesTwo similarly matched entities
Differ in “one” key wayDiffer in “one” key way
E.g. Mondak Study of Newspapers in E.g. Mondak Study of Newspapers in Cleveland and PittsburghCleveland and Pittsburgh
E.g. political coverage on different E.g. political coverage on different networksnetworks
Social ProgramsSocial Programs
Concern- Lack of ControlConcern- Lack of Control
Experimental Methods-AdvantagesExperimental Methods-Advantages
Allow the researcher control over the Allow the researcher control over the situationsituation
Allows for more certainty of measurementAllows for more certainty of measurement
Allow for stronger causal inferences- High Allow for stronger causal inferences- High Internal ValidityInternal Validity Control of extraneous factorsControl of extraneous factors
Experimental Methods-Experimental Methods-DisadvantageDisadvantage
Limits to External ValidityLimits to External Validity Subject PopulationSubject Population Reality of SituationReality of Situation Cannot create some circumstancesCannot create some circumstances Demand EffectsDemand Effects
Cannot manipulate all factorsCannot manipulate all factors PersonalityPersonality Ethical ConsiderationsEthical Considerations
Somewhat weak relationship between attitudes Somewhat weak relationship between attitudes and behaviors? and behaviors?
Experiments- When AppropriateExperiments- When Appropriate
When feasibleWhen feasible
When ethicalWhen ethical
When factors of interest are controllableWhen factors of interest are controllable
Public Opinion ChangePublic Opinion Change
Media StudiesMedia Studies
Time SeriesTime Series
Look at cases at multiple timesLook at cases at multiple times
Panel Study- Re-interview same cases at Panel Study- Re-interview same cases at set pointsset points
Presidential ApprovalPresidential Approval Track from 50s to presentTrack from 50s to present Look at Approval rating of president as Look at Approval rating of president as
Dependent VariableDependent Variable Look at fluctuations in other factorsLook at fluctuations in other factors
Time Series- AdvantagesTime Series- Advantages
Causality- follows temporal patternsCausality- follows temporal patterns
Gives best insight into over time changeGives best insight into over time change
Panels- good for understanding changePanels- good for understanding change
Time Series- DisadvantagesTime Series- Disadvantages
Must have data over timeMust have data over time
Consistency of measures over timeConsistency of measures over time
Causality- confusion?Causality- confusion?
Challenge- empirical generalizationChallenge- empirical generalization
PanelsPanels Drop outsDrop outs Systematic bias in sampleSystematic bias in sample LearningLearning
Time Series- When AppropriateTime Series- When Appropriate
When looking at change over timeWhen looking at change over time
When looking at historical eventsWhen looking at historical events
When looking at development processesWhen looking at development processes
When looking at factors that cannot be When looking at factors that cannot be easily manipulated in lab or do not vary easily manipulated in lab or do not vary cross-sectionallycross-sectionally
Cross SectionalCross Sectional
One timeOne time
Look at multiple casesLook at multiple cases
Cases should have variationCases should have variation
Example- National Election StudyExample- National Election Study
Cross Sectional Studies- SurveyCross Sectional Studies- Survey
Random sample of population of interestRandom sample of population of interest
Ideal Sample greater than 500Ideal Sample greater than 500
Fixed questionnaire Fixed questionnaire
Ask all at roughly same timeAsk all at roughly same time
Ideal for public opinion/voting behaviorIdeal for public opinion/voting behavior
Cross Sectional Designs-Cross Sectional Designs-AdvantagesAdvantages
Does not require as much advanced Does not require as much advanced planningplanning
Good for comparing groups of thingsGood for comparing groups of things
SnapshotSnapshot
Cross Sectional Design- Cross Sectional Design- DisadvantagesDisadvantages
Does not work for certain types of Does not work for certain types of phenomenaphenomena
Limited ability to make causal connectionsLimited ability to make causal connections Temporal issuesTemporal issues
Limited number of casesLimited number of cases
Case StudyCase Study
Focus intense study on one caseFocus intense study on one case
Often qualitativeOften qualitative
Challenge- generalityChallenge- generality
SurveysSurveys
More a tool than a design More a tool than a design Randomly select large number of peopleRandomly select large number of peopleAdminister same questionnaireAdminister same questionnaireMay be cross sectional or time seriesMay be cross sectional or time seriesAllows rich data collectionAllows rich data collectionOften most generalizableOften most generalizableExpensiveExpensiveNot socialNot socialInflexibleInflexible
Focus GroupsFocus Groups
4-10 people together 4-10 people together
Have them discussHave them discuss
Relatively unstructuredRelatively unstructured
Advantage- study more social phenomenaAdvantage- study more social phenomena
Generate new ideasGenerate new ideas
Concern- generalizabilityConcern- generalizability
InterpretationInterpretation