Chapter 9Chapter 9

ExperimentsExperiments

McGraw-Hill/Irwin Copyright © 2011 by The McGraw-Hill Companies, Inc. All Rights Reserved. 

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Learning ObjectivesLearning Objectives

Understand . . .• Uses for experimentation. • Advantages and disadvantages of the

experimental method.• Seven steps of a well-planned experiment. • Internal and external validity with experimental

research designs.• Three types of experimental designs and the

variations of each.

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Experiments Challenge Experiments Challenge PerceptionsPerceptions

“There is no such thing as a failed experiment, only experiments with unexpected outcomes.”

Richard Buckminster Fuller, engineer and architect

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PulsePoint: PulsePoint: Research RevelationResearch Revelation

45 The percent of smartphone users who check their e-mail before they get dressed.

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Causal EvidenceCausal Evidence

Agreement between IVs and DVs

Time order of occurrence

Extraneous variables did not influence DVs

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Causal Evidence?Causal Evidence?

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Evaluation of ExperimentsEvaluation of Experiments

Advantages•Ability to manipulate IV

•Use of control group

•Control of extraneous variables

•Replication possible

•Field experiments possible

Disadvantages•Artificiality of labs

•Non-representative sample

•Expense

•Focus on present and immediate future

•Ethical limitations

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Experimentation in the Research Experimentation in the Research ProcessProcess

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Conducting an ExperimentConducting an Experiment

Specify treatment levels

Control environment

Choose experimental design

Select and assign participants

Pilot-test, revise, and test

Collect data

Analyze data

Specify treatment variables

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Experiment: Placement of Experiment: Placement of Benefits ModuleBenefits Module

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Selecting and Assigning Selecting and Assigning ParticipantsParticipants

Random assignment

Matching

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Random AssignmentRandom Assignment

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Quota Matrix ExampleQuota Matrix Example

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Measurement OptionsMeasurement Options

Scaling techniques

Scaling techniques

Physiologicalmeasures

Physiologicalmeasures

OptionsOptions

Paper-and-pencil testsPaper-and-pencil tests

Observation

Self-administered instruments

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Validity in ExperimentationValidity in Experimentation

ExternalInternal

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Threats to Internal ValidityThreats to Internal Validity

Threats

Maturation History

Testing

Instrumentation

Selection

Statisticalregression

Experimentalmortality

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Additional Threats to Internal Additional Threats to Internal ValidityValidity

Diffusion of treatmentDiffusion of treatment

Compensatory equalizationCompensatory equalization

Compensatory rivalryCompensatory rivalry

Resentful disadvantagedResentful disadvantaged

Local historyLocal history

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Threats to External ValidityThreats to External Validity

Reactivity of testing on X

Interaction of selection and X

Other reactive factors

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Experiments Challenge Experiments Challenge PerceptionsPerceptions

“We need to keep an open mind and approach life as a series of experiments. We need to observe the experiments happening around us and create new ones. Instead of accepting the world as we think it is, we need to keep testing it to find out what it is and what works.”

Jerry Wind Wharton School of Business,

University of Pennsylvania

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Experimental Research DesignsExperimental Research Designs

Pre-experiments

True experiments

Field experiments

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After-Only Case StudyAfter-Only Case Study

X O

Pre-experiment

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One Group Pretest-PosttestOne Group Pretest-Posttest

O1 X O2

Pre-experiment

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Static Group ComparisonStatic Group Comparison

X O1

O2

Pre-experiment

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Pretest-Posttest Control Group Pretest-Posttest Control Group DesignDesign

R O1 X O2

R O3 O4

True experiment

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Posttest-Only Posttest-Only with Control Groupwith Control Group

True experiment

R X O1

R O2

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Nonequivalent Control Group Nonequivalent Control Group DesignDesign

O1 X O2

O3 O4

Field experiment

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Separate Sample Separate Sample Pretest-PosttestPretest-Posttest

R O1 (X)R X O2

Field experiment

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Group Time Series DesignGroup Time Series Design

R O1 O2 O3 X O4 O5 O6

R O7 O8 O9 O10 O11 O12

Field experiment

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Job Enrichment Job Enrichment Quasi-ExperimentQuasi-Experiment

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Experiment: Experiment: Refining Store DesignRefining Store Design

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Experiment: Experiment: The Right Size of FlavorThe Right Size of Flavor

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Key TermsKey Terms

• Blind

• Control group

• Controlled test market

• Dependent variable

• Double-blind

• Environmental control

• Experiment

• Experimental treatment

• External validity

• Field experiment

• Hypothesis

• Independent variable

• Internal validity

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Key TermsKey Terms

• Matching

• Operationalized

• Quota matrix

• Random assignment

• Replication

• Test market– Electronic test market

– Simulated test market

– Standard test market

– Virtual test market

• Treatment levels

• Web-enabled test market

Appendix 9bAppendix 9b

Test MarketsTest Markets

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Test Market SelectionTest Market Selection

IsolationIsolation

Control of distributionControl of distribution

CriteriaCriteria

RepresentativeRepresentative

Over-testing

Media coverage

Multiple locationsMultiple locations

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Types of Test MarketsTypes of Test Markets

Standard Standard

ControlledControlled

ElectronicElectronic

SimulatedSimulated

VirtualVirtual

Web-enabledWeb-enabled

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Test Market CitiesTest Market Cities