Business Research Methods Chap014
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Transcript of Business Research Methods Chap014
14-1
14-2McGraw-Hill/Irwin © 2003 The McGraw-Hill Companies, Inc.,All Rights
Reserved.
Part ThreeSOURCES AND
COLLECTION OF DATA
14-3
Chapter FourteenEXPERIMENTATION
14-4
Variables in Experiments
• Independent variables
• Dependent variables
14-5
Advantages of an Experiment?
• Researcher’s ability to manipulate the independent variable
• Contamination from extraneous variables can be controlled more efficiently
• Convenience • Cost• Replication
14-6
Disadvantages of Experiments
• Artificiality of the laboratory
• Generalization from nonprobability samples
• Larger budgets needed
• Restricted to problems of the present or immediate future
• Ethical limits to manipulation of people
14-7
Experimentation Process
• Select relevant variables
• Specify the treatment levels
• Control the experimental environment
• Choose the experimental design
• Select and assign the participants
• Pilot-test, revise, and test
• Analyze the data
14-8
Ways to Assign Subjects
• Random Assignment
• Matching Assignment– Quota matrix
14-9
Does a Measure Accomplish What it Claims?
• Internal validity
• External validity
14-10
Threats to Internal Validity
• History
• Maturation
• Testing
• Instrumentation
• Selection
• Statistical Regression
• Experimental Mortality
14-11
Threats to External Validity
• The Reactivity of Testing on X
• Interaction of Selection and X
• Other Biasing Effects on X – Artificial setting of testing– Respondents knowledge of testing
14-12
Experimental Designs
• Preexperimental designs
• True experimental designs
• Field experiments
14-13
Design Symbols
X the introduction of an experimental stimulus to the participant
0 a measure or observation activity
R an indication that sample units have been randomly assigned
14-14
Preexperimental Designs
• One-shot case study
• One-group pretest-posttest design
• Static group comparison
14-15
True Experimental Designs
• Pretest-posttest control group design
• Posttest-only control group design
14-16
Operational Extensions of True Designs
• Completely randomized designs
• Randomized block design
• Latin square
• Factorial design
• Covariance analysis
14-17
Field Experiments: Quasi- or Semi-Experiments
• Non Equivalent Control Group Design
• Separate Sample Pretest-Posttest Design
• Group Time Series Design