Unlock document.
This document is partially blurred.
Unlock all pages and 1 million more documents.
Get Access
QUESTIONS FOR REVIEW AND CRITICAL THINKING/ANSWERS
1. If you decide whether or not you want to see a new movie or television program on the basis
of the “coming attractions” or television commercial previews, are you using a sampling
technique? A scientific sampling technique?
Yes, this is a method of sampling. However, this type of sampling is generally not of a scientific
2. Name some possible sampling frames for the following:
a. Electric contractors
b. Tennis players
Obtaining a list of tennis players may be difficult. It may be possible to obtain a list of people
c. Dog owners
A list of dog owners may possibly be obtained from a list of individuals who have sent in a
d. Foreign-car owners
e. Wig and hair goods retailers
f. Minority-owned businesses
g. Men over six feet tall
255
© 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or
duplicated, or posted to a publicly accessible website, in whole or in part.
Chapter Sixteen: Sampling Designs and Sampling Procedures 256
3. Describe the differences between a probability sample and a nonprobability sample.
Briefly, in every probability sample, elements in the population have a known, non-zero
4. In what type of situation is conducting a census more appropriate than sampling? When is
sampling more appropriate than taking a census?
Of course, a researcher investigating a population with an extremely small number of population
elements may elect to conduct a census rather than a sample because the cost, manpower, and
time drawbacks are relatively insignificant. Thus, a company concerned with programmer
5. Comment on the following sampling designs:
a. A citizen’s group interested in generating public and financial support for a new
Those most interested in basketball or those most opposed to the financial program will be most
b. A department store that wishes to examine whether the store is losing or gaining
While the idea of selecting every 10th name in a systematic fashion is fine, it must be questioned
c. A motorcycle manufacturer decided to research consumer characteristics by sending one
This is a poor sampling technique. The manufacturer has delegated the responsibility of sampling
to dealers who may not know anything at all about research. Some dealers may have very
© 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or
duplicated, or posted to a publicly accessible website, in whole or in part.
Chapter Sixteen: Sampling Designs and Sampling Procedures 257
d. An advertising executive suggests that advertising effectiveness be tested in the real
This is a poor sampling design. First, only those individuals who notice the ad can be in the
e. A research company obtains a sample for a focus group through organized groups such as
This technique is often used. It is convenient for the researchers because it often generates a
f. A researcher suggests replacing a consumer diary panel with a sample of customers who
There may be several flaws and biases resulting from a panel where shoppers are strictly
g. A banner ad on a business-oriented website reads, “Are you a large company Sr.
Executive? Qualified execs receive $50 for under 10 minutes of time. Take the survey
now!” Is this an appropriate way to select a sample of business executives?
Business executives are a hard to reach population. This site clearly will not yield a probability
6. When would a researcher use a judgment, or purposive, sample?
Judgment, or purposive, samples are selected based on the researcher’s or some “expert’s”
judgment because they know that some characteristic of the population element is required to
7. A telephone interviewer asks, “I would like to ask you about race. Are you Native American,
Hispanic, African-American, Asian, or white?” After the respondent replies, the interviewer
says, “We have conducted a large number of surveys with people of your background, and
we do not need to question you further. Thank you for your cooperation.” What type of
sampling is likely being used?
© 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or
duplicated, or posted to a publicly accessible website, in whole or in part.
Chapter Sixteen: Sampling Designs and Sampling Procedures 258
8. If researchers know that consumers in various geographical regions respond quite differently
to a product category, such as tomato sauce, is area sampling appropriate? Why or why not?
In area sampling, the sampling unit is no longer the individual element in the population but the
9. What are the benefits of stratified sampling?
Stratified sampling divides the population into groups and subsamples from each group using
10. What geographical units within a metropolitan area are useful for sampling?
11. Researchers often are particularly interested in the subset of a market that contributes most
to sales (for example, heavy beer drinkers or large-volume retailers). What type of
sampling might be best to use with such a subset? Why?
First, the researcher must recognize there are some considerations concerning the target
12. Outline the step-by-step procedure you would use to select the following:
a. A random sample of 150 students at your university
Chances are this list is computerized and a computer program could be used to generate this list.
If the student directory is used, a name could be numbered and a random numbers table could be
© 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or
duplicated, or posted to a publicly accessible website, in whole or in part.
Chapter Sixteen: Sampling Designs and Sampling Procedures 259
b. A quota sample of 50 light users and 50 heavy users of beer in a shopping mall
intercept study
Step 1 will be to contact a sample of individuals. Generally, this will be every nth person who
passes a certain point (e.g., bench area). Then, shoppers will be asked some qualifying questions
c. A stratified sample of 50 mechanical engineers, 40 electrical engineers, and 40 civil
engineers from the subscriber list of an engineering journal.
Because the journal will have a list of engineers who are subscribers, this is the best sampling
13. Selection for jury duty is supposed to be a totally random process. Comment on the
following computer selection procedures, and determine if they are indeed random:
a. A program instructs the computer to scan the list of names and pick names that are next
to those from the last scan.
During a short period, such as six months, jury notices may possibly be sent to several members
of the same family. The reason is that on each computer scan, the programmed guidelines are
b. Three-digit numbers were randomly generated to select jurors from a list of licensed
drivers. If the weight information listed on the license matches the random number, the
person is selected.
A computer programmer who uses weight information as a factor in trying to randomly choose
c. The juror source list was obtained by merging a list of registered voters with a list of
licensed drivers.
Using a list of registered voters and a list of licensed drivers will be inaccurate unless duplicate
14. [Ethics Question] To ensure a good session, a company gathers focus group members from
a list of articulate participants instead of conducting random sampling The client did not
inquire about sample selection when it accepted the proposal. Is this ethical?
© 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or
duplicated, or posted to a publicly accessible website, in whole or in part.
Chapter Sixteen: Sampling Designs and Sampling Procedures 260
This situation brings up two issues. The first is the researcher’s obligation to seek the truth from
a representative sample. The focus group is never considered to be a representative group, but
RESEARCH ACTIVITIES
1. Phone directories are sometimes used for sampling frames. Go to
http://www.reversephonedirectory.com and put in a phone number for someone you know
in the reverse phone search (the number must be a listed number to get results). Comment
on the accuracy of the information and the appropriateness of phone directories as a
representative sample.
This used to be free, but now it appears that there is a charge to get the information. When
12. [Internet Question] Go to the U.S. Census Bureau’s home page at http://www.census.gov.
Profiles of every state are available (you may find the “Quick Facts” or “Population
Finder” helpful) from this website. Find the data for Louisiana. Suppose a representative
sample of the state of Louisiana is used to represent the current U.S. population. How well
does Louisiana represent the current U.S. population? How well does Louisiana represent
California or Maine? Use the profiles of the states and of the country to form your opinion.
Students’ responses will vary because there is a considerable amount of information available
CASE 16.1 Who’s Fishing?
Objective: To enable students to develop a sampling plan.
Summary: Although interest groups express concerns about the impact of saltwater fishers on
the fish population, no one really knows how many people fish for recreation or how many fish
they catch. How could a marketer get an accurate sample? Some suggestions include contacting
residents of coastal counties using random-digit dialing, use state fishing license records, or have
charter fishing businesses collect data.
Questions
1. Imagine that an agency or business has asked for help in gathering data about the number of
sports anglers who fish off the coast of Georgia. What advice would you give about
sampling? What method or combination of methods would generate the best results?
© 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or
duplicated, or posted to a publicly accessible website, in whole or in part.
Chapter Sixteen: Sampling Designs and Sampling Procedures 261
Sports anglers who fish off the coast of Georgia are not necessarily Georgia residents as some
might travel to fish there. While the first two suggestions are reasonable, as stated in the case,
using random-digit dialing will result in reaching a lot of people who do not fish or fish
2. What other criteria besides accuracy would you expect to consider? What sampling methods
could help you meet those criteria?
Besides accuracy, there are a number of criteria that are considered when sampling: resources,
time, advance knowledge of the population (i.e., availability of lists of population members), and
CASE 16.2 Scientific Telephone Samples
Objective: The objective of this case is to illustrate how sampling frames may be purchased
from organizations that specialize in providing mailing lists for research.
Summary: STS uses a random digit dialing method for its databases of all working residential
telephone exchanges in the United States.
Questions
1. Evaluate the geographic options offered by STS. Do they seem to cover all the bases?
As the case describes, STS can furnish national, state, county, and smaller samples. They provide
2. Evaluate the STS method of random-digit dialing.
The procedure is sound. The company first checks the Central Office Codes to make sure each
number in the database meets the client’s specifications for residential households. For example,
© 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or
duplicated, or posted to a publicly accessible website, in whole or in part.
