Research Methods in MIS: Experimentation

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Research Methods in MISExperimentation

• Dr. Deepak Khazanchi

Acknowledgment Some of the information in this
presentation is Based on Cooper and Schindler
(2000) and Sproull (1996).
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Variables in Experiments

• Independent variables
• Treatment or experimental variable The
  independent variable that is manipulated by the
  researcher so that different groups of subjects
  receive different kinds or amounts.
• Dependent variables

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Advantages of an Experiment?

• Researchers ability to manipulate the
  independent variable
• Contamination from extraneous variables can be
  controlled more efficiently
• Convenience
• Cost
• Replication

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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

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Experimentation Process

• Select relevant variables
• Specify the treatment levels
• Control the experimental environment
• Choose the experimental design
• Select and assign the subjects
• Pilot-test, revise, and test
• Analyze the data

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Ways to Assign Subjects

• Random Assignment
• Matching Assignment
• Quota matrix

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Does a Measure Accomplish What it Claims?

• Internal validity
• External validity

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Threats to Internal Validity

• History
• Maturation
• Testing
• Instrumentation

• Selection
• Statistical Regression
• Experimental Mortality

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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

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Experimental Designs

• Preexperimental designs
• True experimental designs
• Field experiments

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Design Symbols

• X the introduction of an experimental stimulus to
  the respondent
• 0 a measure or observation activity
• R an indication that sample units have been
  randomly assigned

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Preexperimental Designs

• One-shot case study
• One-group pretest-posttest design
• Static group comparison

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True Experimental Designs

• Pretest-posttest control group design
• Posttest-only control group design

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Operational Extensions of True Designs

• Completely randomized designs
• Randomized block design
• Latin square
• Factorial design
• Covariance analysis

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Field Experiments Quasi- or Semi-Experiments

• Non Equivalent Control Group Design
• Separate Sample Pretest-Posttest Design
• Group Time Series Design