Global Motors
After some deliberation, Cory Rogers of CMG Research and Nick Thomas of Global Motors are now confronted with the data collection method for the Global Motors survey down to the use of an online panel. With the data collection method and questionnaire design settled, Global Motors are now confronted with the data collection step in the marketing research process. While the size of the sample is not precisely known, it is understood that it will be "quite large." However, the principals involved realize that a large sample size will be useless if the sample selection process fails to garner a representative sample.

With some thought and a bit of discussion, the principals have come to agreement that the population is all households in the United States. The major issue to resolve in these population definition debates was whether to include individuals who do not own vehicles. Eventually, it was decided to include the non-owners, as the development and ultimate manufacture of the new models has a five-year horizon, and it is possible that in that time period, non owners could move into the vehicle owner category. At the same time, the attractiveness of electric and/or hybrid vehicles may be great for vehicle non owners, and it did not seem prudent to leave out this possibly significant segment of the potential vehicle-buying public. Recent census estimates place the number of U.S. households to be approximately 115 million units.

1. Specify the population definition.

2. If a probability sampling method is to be used, what would be a reasonable sample frame for
a. A telephone survey
b. A mail survey
c. An online survey

3. What are the practical problems involved with drawing a simple random sample of American households (regardless of the survey method)?

4. If random digit dialing was used for the sample plan, what are the advantages and disadvantages of this sample method?

5. Should Global Motors use a probability online panel of U.S. households such as the one maintained by Knowledge Networks, Inc.? With respect to sample design, what are the advantages and disadvantages involved with using this approach? (You may want to review Knowledge Networks, Inc., services by visiting its website at www.knowledgenetworks.com.)