1 marketing research week 3 session a ibms term 2, 2008-09
TRANSCRIPT
![Page 1: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/1.jpg)
MARKETING MARKETING RESEARCHRESEARCH
Week 3Week 3Session ASession A
IBMS Term 2, 2008-09IBMS Term 2, 2008-09
![Page 2: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/2.jpg)
Today:
•2 x Lectures
•2 x Project Sessions• Project Brief Due – Fri 13th Mar
• Questionnaire Due – Fri 20th Mar
• Coaching Sessions Throughout the Week (W.Moes)
This Week
![Page 3: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/3.jpg)
Today:
•Lecture: Sample Selection (Ch 12)
Break
•Lecture: Sample Selection (Ch 12)
•Class Activity: Review Questions & Case
![Page 4: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/4.jpg)
Determining How to Select a Sample
![Page 5: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/5.jpg)
5
Basic Concepts in Sampling
• Population: the entire group under study as defined by research objectives
• Census: an accounting of the complete population (a list)
![Page 6: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/6.jpg)
6
Basic Concepts in Sampling
• Sample: a subset of the population that should represent the entire group
• Sample unit: the basic level of investigation
![Page 7: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/7.jpg)
7
Basic Concepts in Sampling
• Sampling error: any error in a survey that occurs because a sampling is used– Selection problems– Incorrect sample size
• A sample frame: a master list of the entire population– Telephone List– Customer List– Email List with email addresses
![Page 8: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/8.jpg)
8
Basic Concepts in Sampling
• Sample frame error: the sample frame fails to account for all of the population– a telephone book listing does not
contain unlisted numbers– A list of visitors to the EPBS Career
Beurs Stand does not include people that could not make it to the Beurs.
![Page 9: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/9.jpg)
9
REMEMBER!
• Two types of errors in sampling:– Sampling error– Sample frame error
![Page 10: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/10.jpg)
10
Reasons for Taking a Sample
• Practical considerations such as cost and population size
• Inability of researcher to analyze huge amounts of data generated by census
• Samples can produce precise results
![Page 11: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/11.jpg)
11
Two Basic Sampling Methods
• Probability samples: members of the population have a known chance (probability) of being selected into the sample
• Non-probability samples: probability of selecting members from the population into the sample are unknown
![Page 12: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/12.jpg)
12
Probability Sampling Methods
(probability is known)
• Simple random sampling
• Systematic sampling
• Cluster sampling
• Stratified sampling
![Page 13: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/13.jpg)
13
Probability Sampling Methods
![Page 14: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/14.jpg)
14
Probability Sampling:Simple Random Sampling
• Simple random sampling: the probability of being selected into the sample is “known” and equal for all members of the population
– E.g., Blind Draw Method
– Random Numbers Method
![Page 15: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/15.jpg)
15
Probability Sampling:Simple Random Sampling
– Advantage: • Known and equal chance of selection
– Disadvantages:• Complete accounting of population
needed• Cumbersome to provide unique
designations to every population member
![Page 16: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/16.jpg)
16
Probability SamplingSystematic Sampling
• Systematic sampling: way to select a random sample from a directory or list that is much more efficient than simple random sampling
– Skip interval=population list size/sample size
![Page 17: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/17.jpg)
17
Probability SamplingSystematic Sampling
– Advantages: • Approximate known and equal
chance of selection…it is a probability sample plan
• Efficiency…do not need to designate every population member
• Less expensive…faster than SRS
– Disadvantage:• Small loss in sampling precision
![Page 18: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/18.jpg)
18
Probability SamplingCluster Sampling
• Cluster sampling: method in which the population is divided into groups, any of which can be considered a representative sample– Area sampling
![Page 19: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/19.jpg)
19
Probability SamplingCluster Sampling
– Advantage:
• Economic efficiency…faster and less expensive than SRS
– Disadvantage:
• Cluster specification error…the more homogeneous the clusters, the more precise the sample results
![Page 20: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/20.jpg)
20
Stratified Sampling
• When the researcher knows the answers to the research question are likely to vary by subgroups…
![Page 21: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/21.jpg)
21
Stratified Sampling
– Research Question:
“To what extent do you value your college degree?”
Answers are on a five point scale: 1= “Not valued” and 5= “Highly valued”
![Page 22: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/22.jpg)
22
Stratified Sampling
![Page 23: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/23.jpg)
23
Probability SamplingStratified Sampling
• Stratified sampling: method in which the population is separated into different strata and a sample is taken from each stratum
![Page 24: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/24.jpg)
24
Probability SamplingStratified Sampling
– Advantage: • More accurate overall sample of
skewed population…see next slide for WHY
– Disadvantage:• More complex sampling plan
requiring different sample size for each stratum
![Page 25: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/25.jpg)
25
Break
• 15 minutes
![Page 26: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/26.jpg)
26
Nonprobability Sampling
• With nonprobability sampling methods selection is not based on fairness, equity, or equal chance.
– Convenience sampling
– Judgment sampling
– Referral sampling
– Quota sampling
![Page 27: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/27.jpg)
27
Nonprobability Sampling
• May not be representative but they are still used very often. Why?
– Decision makers want fast, relatively inexpensive answers… nonprobability samples are faster and less costly than probability samples.
![Page 28: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/28.jpg)
28
Nonprobability Sampling
• May not be representative but they are still used very often. Why?
– Decision makers can make a decision based upon what 100 or 200 or 300 people say…they don’t feel they need a probability sample.
![Page 29: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/29.jpg)
29
Nonprobability Sampling
• Convenience samples: samples drawn at the convenience of the interviewer
– Error occurs in the form of members of the population who are infrequent or nonusers of that location
![Page 30: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/30.jpg)
30
Nonprobability Sampling
• Judgment samples: samples that require a judgment or an “educated guess” as to who should represent the population
– Subjectivity enters in here, and certain members will have a smaller chance of selection than others
![Page 31: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/31.jpg)
31
Nonprobability Sampling
• Referral samples (snowball samples): samples which require respondents to provide the names of additional respondents
– Members of the population who are less known, disliked, or whose opinions conflict with the respondent have a low probability of being selected
![Page 32: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/32.jpg)
32
Nonprobability Sampling
• Quota samples: samples that use a specific quota of certain types of individuals to be interviewed
– Often used to ensure that convenience samples will have desired proportion of different respondent classes
![Page 33: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/33.jpg)
33
Online Sampling Techniques
• Random online intercept sampling: relies on a random selection of Web site visitors
• Invitation online sampling: is when potential respondents are alerted that they may fill out a questionnaire that is hosted at a specific Web site
![Page 34: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/34.jpg)
34
Online Sampling Techniques
• Online panel sampling: refers to consumer or other respondent panels that are set up by marketing research companies for the explicit purpose of conducting surveys with representative samples
![Page 35: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/35.jpg)
35
Developing a Sample Plan
• Sample plan: definite sequence of steps that the researcher goes through in order to draw and ultimately arrive at the final sample
![Page 36: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/36.jpg)
36
Developing a Sample Plan
1. Define the relevant population.
2. Obtain a listing of the population.
– The incidence rate is the percentage of people on a list who qualify as members of the population
3. Design the sample plan (size and method).
![Page 37: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/37.jpg)
37
Developing a Sample Plan
4. Draw the sample.– Substitution methods:
• Drop-down substitution • Oversampling • Resampling
![Page 38: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/38.jpg)
38
Developing a Sample Plan
5. Validate the sample.
– Sample validation is a process in which the researcher inspects some characteristic(s) of the sample to judge how well it represents the population.
6. Resample, if necessary.
![Page 39: 1 MARKETING RESEARCH Week 3 Session A IBMS Term 2, 2008-09](https://reader034.vdocuments.site/reader034/viewer/2022042821/56649e225503460f94b0f0b2/html5/thumbnails/39.jpg)
39
Class Activity
• In your groups, draft up a sample plan for
your Research Project. Submit to the
teacher and then you are finished for this
teaching session.