Chapter 13 - Experiments. In this chapter, the following content will be discussed: experimental vs. descriptive research, what constitutes causality? direction of causation issue, conditions for valid causal inference, laboratory and field experiments,...
1 Marketing Research Aaker, Kumar, Leone and Day Twelfth Edition Instructor’s Chapter Thirteen Experimentation Marketing Research 12th Edition Experiments • Studies in which conditions are controlled so that one or more independent variable(s) can be manipulated to test a hypothesis about a dependent variable Marketing Research 12th Edition Experimental vs. Descriptive Research Marketing Research 12th Edition What Constitutes Causality? • • • • A change in one variable will produce a change in another Concept of a precondition influencing a variable of interest Time Sequence Lack of association suggests absence of causation Attitude Behavior Marketing Research 12th Edition Direction of Causation Issue Approach 1: Determining the direction of causation ▫ Draw on logic and previous theory Whether one of the variables is relatively fixed and unalterable Approach 2: Consider the fact that there is usually a time lag exists between cause and effect ▫ The causal variable should have a positive association with the effect variable lagged in time Marketing Research 12th Edition Conditions for Valid Causal Inference Marketing Research 12th Edition Laboratory and Field experiments Marketing Research 12th Edition Laboratory Experiments • • • • • • Experiments in which the experimental treatment is introduced in an artificial or laboratory setting Tend to be artificial Testing effect exists as respondents are aware of being in a test and may not respond naturally Results may not have external validity Least costly and allow experimenter greater control over the experiment Alternative explanations of results are reduced, increasing internal validity Marketing Research 12th Edition 10 Field Experiments • • • • • • Research study in which one or more independent variables are manipulated by the experimenter under carefully controlled conditions as the situation will permit Experimental treatment or intervention introduced in a completely natural setting Response tends to be natural Tend to have much greater external validity Difficult to control Competing explanations for results exist Marketing Research 12th Edition 26 QuasiExperimental Designs • • Offer some degree of control but there is no random assignment of variables Provide more measurements and more information than pre experimental design Time Series Designs • Series of measurements are employed during which an experimental treatment occurs EG O1 O2 O3 O4 X O5 O6 O7 O8 Marketing Research 12th Edition 27 Time Series Designs Marketing Research 12th Edition 28 Quasiexperimental Designs (Contd.) Trend Studies • Measures over time come from succession of separate random samples from the same population Continuous Panel Studies • Collect a series of measurements on the same sample of test units over an extended period of time Marketing Research 12th Edition 29 Statistical Designs Completely Randomized Design • Any number of treatments can be assigned to test units on a random basis EG1 R X1 O1 EG2 R X2 O2 EG3 R X3 O3 ` Marketing Research 12th Edition 30 Statistical Designs (Contd.) Randomized Block Design • • • Employs the randomization process for all variables Matching ensures that there are no differences between test samples on matched variables Matching and randomization are combined in randomized block design EG1 R X O1 CG1 R O2 EG2 R X O3 CG2 R O4 Marketing Research 12th Edition 31 Statistical Designs (Contd.) Latin Square Design • • • Reduces number of groups involved when interaction between the treatment levels and control variables are unimportant Requires same number of rows, columns, and treatment levels Cannot be used to determine interaction effects Marketing Research 12th Edition Latin Square Design Example 32 Marketing Research 12th Edition 33 Statistical Designs (Contd.) Factorial Designs • • • Two or more experimental variables are considered simultaneously Each combination of the experimental treatment levels applies to randomly selected groups EG1 R X1 (Hi Adv, Hi Price) O1 n 6 EG2 R X2 (Hi Adv, Low Price) O2 n 6 EG3 R X3 (Low Adv, Hi Price) O3 n 6 EG4 R X4 (Low Adv, Low Price) O4 n 6 EG5 R X5 (No Adv, Hi Price) O5 n 6 EG6 R X6 (No Adv, Low Price) O3 n 6 Provides the ability to determine interactive effects of pairs of experimental variables and the main effect Marketing Research 12th Edition 34 Interactive Effects Marketing Research 12th Edition 35 Guidelines for Conducting Experimental Research • • • • • • • Recognition of and statement of the problem should be clear and generally acceptable Choice of factors and levels – considering control and measurement Selection of the response variable must provide useful information about process under study Choice of experimental design – considering sample size, Selection of suitable run order for experimental trials, determination of whether or not blocking or other randomization restrictions are involved Performing the experiment – monitor carefully to avoid errors Data Analysis – use statistical methods Conclusion and Recommendations – draw practical conclusions and recommend a course of action Marketing Research 12th Edition 36 Limitations of Experiments • Cost Involved • Time Considerations • Security ▫ Field experiment exposes marketing program in the marketplace ▫ Difficult to hide from competitors Marketing Research 12th Edition 37 Limitations of Experiments (Contd.) • Implementation Problems ▫ Difficult to gain cooperation within the organization ▫ Contamination may occur in experiments involving market areas due to inability to confine the treatment to designated experimental area ▫ Variability in behavior across test units can be so large that it is difficult to detect experimental Marketing Research 12th Edition 38 Uncertain Persistency of Results Causes: ▫ High rates of technological, economic, or social change in the market environment ▫ Aggressive competitive behavior Marketing Research 12th Edition 39 Simulated Test Marketing • • • • To overcome limitations posed by experiments such as test marketing in terms of cost, time involved and sabotage or imitation by competition Enables firms to screen new ideas during the early phases of development and channel resources to maximize the potential for success Widely used by the packaged goods industry as an aid for effective business planning Examples of companies involved in STM research BASES, ASSESSOR and Yankelovich. Marketing Research 12th Edition 40 End of Chapter Thirteen Marketing Research 12th Edition ... effect variable lagged in time Marketing Research 12th Edition Conditions for Valid Causal Inference Marketing Research 12th Edition Laboratory and Field experiments Marketing Research 12th Edition Laboratory Experiments... more independent variable(s) can be manipulated to test a hypothesis about a dependent variable Marketing Research 12th Edition Experimental vs. Descriptive Research Marketing Research 12th Edition What Constitutes Causality? • • •...2 Chapter Thirteen Experimentation Marketing Research 12th Edition Experiments • Studies in which conditions are controlled so that one or