Descriptive and Causal Research Designs

1. Descriptive and Causal Research Designs Chapter 6

2. SLIDE 6-1 Classification of Descriptive Studies Continuous Panel Longitudinal Discontinuous Panel Descriptive Studies Cross Sectional Sample Survey

3. • allows turnover analysis if panel is continuous • allows collection of much more classification information from respondents • allows longer and more exacting interviews • produces fewer errors in reporting past behavior because of natural forgetting • produces fewer interviewer—respondent interaction errors • tends to produce more representative samples of the population of interest • produces fewer errors due to respondent’s behavior being affected by the measurement task • allows the investigation of many more relationships SLIDE 6-2 Longitudinal vs. Cross-Sectional Data LONGITUDINAL DATA CROSS-SECTIONAL DATA

4. Brand Purchased During First Time Period t1 During Second Time Period t2 A B C D Total 230 310 340 120 1,000 280 290 310 120 1,000 SLIDE 6-3 Brand Switching Example: Number of Families in Panel Purchasing Each Brand

5. During Second Time Period t2 Bought A Bought B Bought C Bought D Total Bought A Bought B Bought C Bought D Total 210 0 0 70 280 20 260 0 10 290 0 50 260 0 310 0 0 80 40 120 230 310 340 120 1,000 During First Time Period t1 SLIDE 6-4 Brand Switching Example: Number of Families Purchasing Each Brand in Each Period

6. During Second Time Period t2 Bought A Bought B Bought C Bought D Total Bought A Bought B Bought C Bought D .913 .000 .000 .583 .087 .839 .000 .083 .000 .161 .785 .000 .000 .000 .235 .333 1.000 1.000 1.000 1.000 During First Time Period t1 SLIDE 6-5 Brand Switching Example: Proportion of Families Purchasing Each Brand in Each Period

7. SLIDE 6-6 Types of Evidence That Supports a Causal Inference • Concomitant variation—evidence of the extent to which X and Y occur together or vary together in the way predicted by the hypothesis • Time order of occurrence of variables—evidence that shows X occurs before Y • Elimination of other possible causal factors—evidence that allows the elimination of factors other than X as the cause of Y X—the presumed cause (independent variable) Y—the presumed effect (dependent variable)

8. SLIDE 6-7 Types of Experiments Laboratory Experiment Research investigation in which Investigator creates a situation with exact conditions so as to control some, and manipulate other, variables Experiment Scientific investigation in which an investigator manipulates and controls one or more independent variables and observes the degree to which the dependent variable or variables change Field Experiment Research study in a realistic situation in which one or more independent variables are manipulated by the experimenter Under as carefully controlled conditions as the situation will permit

9. Simulated Test Market Promising Not Promising Abort Controlled Test Market Promising Not Promising Abort Standard Test Market Not Promising Abort Promising National Rollout SLIDE 6-8 Relationship Among Types of Test Markets

10. SLIDE 6-9 Relative Advantages and Disadvantages of Different Types of Test Markets simulated controlled standard Speed 1 2 3 Cost 1 2 3 Security 1 2 3 Validity * internal 1 2 3 * external 3 2 1 Prediction accuracy 3 2 1 1 = most favorable 2 = least favorable