Transcript Statistics for Marketing and Consumer Research

Primary data collection
Chapter 3
Statistics for Marketing & Consumer Research
Copyright © 2008 - Mario Mazzocchi
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Some alternatives to the use of
secondary data
• Primary data collection
• Experimental methods (experiments under
controlled conditions)
• Ethnographic methods (targeted to the
study of cultures, immersion in a cultural
community to record behaviors)
• Test marketing (actually launching the
marketing activity on a small scale)
• Qualitative research methods
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Qualitative research methods
• Exploratory research: gathering insights and
understanding of the research problem
• Loose definition of information needs
• Very flexible and almost unstructured research
processes
• Samples are not necessarily representative and
often very small
• Useful to explore emotional and effective
relationships (e.g. a TV advert is funny or not), or
for sensitive topics that people are likely to be
unwilling or unable to answer.
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Running qualitative research
• Objectives of qualitative research:
(1) obtain an adequate definition of the research problem
(2) develop specific hypothesis to be tested through quantitative
research
(3) identify key variables which will require a specific quantitative
analysis
(4) set the priorities for further research
• Direct methods (straight and undisguised collection): focus
groups, in-depth interviews and panels such as the Delphi
method and nominal group techniques
• Indirect methods (disguised objectives, indirect
collections); psychology-based projective techniques like
association, completion, construction and expression.
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Errors in primary surveys
Source of error
Description
A
SAMPLING ERROR
Error associated purely with the fact that we observe a sample rather than the whole population, with
probabilistic samples that can be estimated
B
NON-SAMPLING
ERROR
(B1+B2+B3+B4+B5)
This error includes all other sources of errors that do not depend on the sampling process. Nonsampling errors can be random or non-random (biases), where the latter are more likely to affect the
estimation results
B1
Sampling frame errors
Some of the population items are not represented in the sampling frame
B2
Non response errors
(B21+B22)
Some of the sampled units do not participate to the survey
B21
Not-at-home
The sampled unit could not be contacted
B22
Refusals
The sampled unit refused to cooperate
B3
Researcher errors
All those errors imputable to problems in the research design, such as errors in defining the population,
inappropriate administration methods, inconsistencies between the research objectives and the
questionnaire, errors in data processing, etc.
B4
Interviewer errors
Errors due to inappropriate actions of the interviewer. These include inappropriate selection of the
respondents, errors in asking questions, errors in recording the responses or even fabricating them.
B5
Respondent errors
While participating in the survey, the respondent provides (willingly or unwillingly) incorrect answers
or does not answer to some of the questions
TOTAL SURVEY ERROR
(A+B)
Overall error
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Sources of error
• Sampling error: probabilistic sampling allows to
measure and control this error component
• In many situations the sampling error is low
compared to non-sampling and potentially
systematic errors (especially when the proportion
of non-respondent is high)
• Systematic errors: cannot be quantified prior to
the survey and difficult to be detected even after
the field work)
• Prevention of systematic errors is vital
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Primary research process
1.
2.
3.
4.
Clearly formulate the research objectives
Set the survey research design
Design data-collection method and forms
Design sample and collect data
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Formulating the research objectives
• A clear definition of the research problem is needed
through:
•
•
•
•
Discussion with the final user.
Interviews with experts on the topic
Analysis of secondary data
Qualitative research
• Then the precise research questions can be derived from
the research problem
• Break down the research problem into components
• At this stage the theoretical and statistical framework needs to be
chosen
• Questions can be expressed through hypotheses to be tested
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The survey research design
in seven steps
1)
Identification of the reference population and sampling
frame
2) Choice of sampling criteria
3) Definition of the estimation methodology for making
inference on the surveyed parameters
4) Choice of sample size
5) Choice of the data-collection method
6) Questionnaire design
7) Cost evaluation
Not necessarily in this order – rather interlinked decisions
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Reference population and
sampling frame
• Sampling frame: the complete list of all elements in a
population which can be used to extract a sample
• The survey gathers information about the population
• Definition of the reference population:
• identification of the basic unit to be surveyed (the individual
consumer, the household, geographic areas, etc.), which will
provide the basis for selecting the sampling units
• The population and sampling units do not necessarily coincide with
the basic elements of the population (e.g. household as
sampling\population units, then measurements on single individuals)
• The reference population needs to be reflected by an appropriate
sampling frame – thus it might not be the ideal one, but simply the
feasible one
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Sampling criteria
• Choice of the type of sampling (see lecture 5)
• probabilistic versus non probabilistic
• stratified versus simple random sampling
• deep implications in terms of costs and precision levels
• The choice is constrained by other decisions
• The sampling frame
• Variables available in the sampling frame (stratification)
• Interview method (e.g. telephone, mail, mall-intercept)
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Estimation methodology (inference)
Inference: the generalization process which allows to
project characteristics observed in a sample to the
whole population of interest
• Sample estimators depend on the sampling criteria
• The methodological choice (average, proportions,
models, classification, etc.) is relevant to:
• Questionnaire design
• Sample size
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Sample size
• Mathematical rules (see lecture 5): size is a
function of the precision levels and sampling
design
• Other issues:
• Non-response rates (which depend on the administration
method) need to be taken into account
• When non-response rates are high and non-responses are
not random sampling error is negligible compared to
non-sampling errors.
• If information on sub-groups of the target population is
relevant, representativeness requires an increase of the
overall sample size.
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Data collection method
• Choice of the administration method (face-to-face
interviews, telephone interviews, electronic
surveys, postal surveys) is related to:
•
•
•
•
sampling method
sampling size
sampling frame
questionnaire design
• This is one of the first decisions to be taken,
usually based on:
• Number of questions and duration of the interview
• Type of question (sensitive or not)
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Questionnaire
• Key factors for developing questionnaire
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•
•
•
Research objectives
Administration methods
Characteristics of the target population
Methodologies chosen for statistical processing
• Qualitative methods and pre-testing are key
to quality improvement
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Cost-effectiveness
• The ideal research design might be the most expensive one
• Compromise is often necessary
• Strategy
•
•
•
Cost the ideal research design
Prioritize issues
Identify cost reductions
• The seven steps of the research design are not sequential,
but are considered and adjusted simultaneously
• Strategy:
•
•
•
Choose the ideal administration method
Define the questionnaire length and sample size according to the
administration method and budget constraint
If the solution is not acceptable change the administration method
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Final steps
• After determining all steps of the research design,
the questionnaire is drafted considering:
• Consistency with research objectives
• Internal coherence
• Potential source of bias
• Draft questionnaire is pre-tested through a pilot
study (this may include pilot statistical analysis)
• The draft questionnaire is adjusted and finalized
(e.g. to meet duration constraints)
• The sample is extracted
• Field work!
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Administration methods
•
•
•
•
Telephone interviews
Personal interviews
Mail surveys
Electronic interviews
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Telephone interviews
• Traditional interviewing (a phone, a pencil and a
questionnaire)
• Computer Assisted Telephone Interviewing (CATI) –
computerised questionnaire administered to
respondents through the phone
•Software checks for consistency
and completeness
•Reduces the interviewers’ errors
•May control sampling procedures
(e.g. random dialling)
•Measures quality parameters (e.g.
duration)
•Data are ready to use
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•Cannot reach those without a
telephone
•It is expensive (at least 700-1000
interviews to justify costs)
•Not very suitable for open
questions
•Interviews should be short
(twelve to fifteen minutes)
•Use of stimuli is not possible
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Personal interviews
• In-home (interviewer visits respondent at home)
•Personal contact with interviewer
•Highly Expensive
•Skilled interviewers increase quality
•Interviewer influence/bias
•Longer duration
•Wariness of respondents
•High response rate
• Mall-intercept (respondent was stopped outside shops or in the street)
•Cheaper
•Difficulties in obtaining sensitive
•Easy use of stimuli
information (no anonymity)
•Can be run without sampling frame
•High social desirability
• Computer-Assisted (CAPI) with interviewer
•Increased involvement of respondent
•On-screen and off-screen stimuli
•Interviews may last even longer
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•Limited sampling control
•Slower (but time perception varies)
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Mail surveys
• Mail interviews (Fax for businesses)
•Cheap
•Optimal for sensitive
questions/anonymity/social desirability
•No interviewer bias
•Very low response rate
•Selection bias / low sample control
•Very slow
• Mail panels
•Allow for longitudinal (time
comparison) design
•Higher response rate
•Higher sample control
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•More expensive
•Low control of data collection
environment
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Electronic interviews
• E-mail (ASCII/text message)
•Very cheap
•Quick
•No interviewer bias
•Selection bias
•Requires data entry before analysis
•Low quality of data
•Low sample control
•Low response rate (and decreasing)
• Web-based (HTML/Java)
•Allow for (some type of) stimuli
•Logic/consistency checks (CAWI)
•Higher sample control
•Anonimity/Sensitive questions
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•(Very) low sample control
•Selection bias
•Problems in compiling lists
•Even lower response rate
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The questionnaire
• Key step in ensuring consistency between the
actual measurement and the targeted
measurement
• Questionnaires are a likely source of non-sampling
error
•
•
•
Potential discordance between the information
provided by the respondent and the interpretation by
the researcher
Bad questionnaires increase non-response errors
Ill-posed questions raise response errors (e.g.
inaccurate answers)
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Steps for a good questionnaire
• Eight steps towards a good questionnaire:
1.Specify the information to be collected
2.Define the information collected by each individual
question
3.Choose structure and measurement scale
4.Determine the wording of each questions
5.Sort the questions (and possibly divide them into
sections)
6.Code the questions and simulate statistical processing
7.Write an appropriate introduction / presentation and
define the layout
8.Pilot the questionnaire and revise where necessary
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Specify the information to be collected
• Exploit preliminary qualitative research
(e.g. focus groups)
• Ensure consistency between the research
objective and the research questions
• The use of a theoretical framework needs
to be considered at this stage
• Take into account the chosen statistical
methodology
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Example
(1) Research objective: understanding the radio
listening habits of a population
(2) Research questions: (a) when do people listen to
radio; (b) where do people listen to radio; (c) what
radio stations they listen to
(3) Disaggregation of research questions: e.g. (a)
could become (a1) time of the day when they
listen to radio; (a2) days of the week when they
listen to radio; (a3) activities they do while
listening to radio; (a4) seasonal differences in
radio listening habits
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Information collected by each
individual questions
• Is the question necessary?
• Unnecessary questions should be eliminated, unless they serve for
other purposes (e.g. disguise the purpose of sponsorship, etc.)
• Is a single question sufficient?
• When do you listen to the radio? What does it mean? Two potential
interpretations:
• on which days or at what time of the day? Better:
• How often do you listen to the radio? (number of days per week)
• At what time of the day do you typically listen to the radio?
• Why do you eat Sainsbury pizza?
• Define variables / prepare a draft spreadsheet
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Choose structure and measurement
scale
• Unstructured question (open-ended, free response)
• Good as first questions on a topic
• Less biasing influence (but interviewer bias)
• Coding of responses is costly and time-consuming
• Structured questions
• Multiple Choice (A, B or C?) – order bias
• Dichotomous (Yes or No or Don"t know) – question wording bias
• Scales (from one to ten)
• Choice of measurement scale (see lecture 1)
• Sensitivity issues may be dealt by indirect elicitation
techniques
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Overcoming problems in answering
• Factors that might lead to unanswered
questions or inaccurate answers:
•
•
•
•
Lack of information
Lack of memory
Incapacity to articulate certain responses
Unwillingness to answer (sensitive information,
too much effort, the question/context is
perceived as inappropriate)
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Techniques to get sensitive questions
answered
•
•
•
•
•
Hide the question among a group of innocent
questions
State that the behavior of interest is common or
the usefulness of an answer
Use the third-person technique
Provide categories instead of asking for figures
Use randomised techniques (but you lose any
linkage with other questions)
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Randomised techniques
Please flip a coin.
If you get a head, please answer to question
A, if you get a tail please answer to
question B.
A. Are you enjoying this lecture?
B. Are you a female?
YES
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NO
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Interpretation of randomised questions
• We got the following results for the question:
YES: 40%
NO: 60%
• We know that 60% of our respondents are female
and 40% are male
• We know that the probability of getting a head or a
tail is 50%
Pr(Yes)  50%*( A  yes)  50%*( B  yes)
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Result
Pr(Yes)  0.5*( A  yes)  0.5*( B  yes)
40%  0.5*( A  yes)  0.5*60%
40%  0.5*60%
Pr( A  Yes ) 
 20%
0.5
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Wording
•
•
•
•
•
•
•
•
Avoid long and elaborate questions
Use wording compatible with the measurement scale
Use ordinary words
Avoid ambiguous words (no generally, frequent etc.)
Avoid phrasing which suggests the answer (Do you think people
should listen more to the radio and watch less television?)
Avoid questions which need a particular effort for memory,
computing, etc. (How many hours per year do you listen to
the radio?; What is the frequency of your favourite radio
station?)
Avoid questions that are too generic (Why do you like radio
programs?)
Use positive and negative statements (advisable to use dual
statements for different respondents; e.g. Is this cheese soft?
Is this cheese hard?)
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Sorting questions
• Use good opening (ice-breaking) questions (What is
your current favourite radio hit?)
• Place difficult and sensitive question towards the
end (What is your salary?)
• Ask basic information first; target variables (Do you
own a radio?)
• Ask classification and identification questions at
the end (age, gender, etc.)
• General questions should precede specific
questions
• Follow a logical order (a flow chart may help)
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Code the question and test statistical
processing
• Code the questions in a way that is functional for
an electronic data sheet (or statistical package)
• A good strategy is to simulate data (or use pilot
data) to test the statistical techniques
• Try to anticipate potential problems in terms of
lack of variability (e.g. all respondents giving the
same answers, number of items in a measurement
scale, etc.)
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Introduction presentation and layout
• Decide whether it is good to mention who
promotes the research (trust versus perception of
vested interests)
• Consider pros and cons of provision of incentives to
participate (higher response rates vs. selection
bias)
• Professional appearance in self-administered
questionnaires
• Avoid splitting questions across pages
• Consider positioning key question close to the top
of the page
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Pilot and pre-testing
• Pilot study: preliminary test on the questionnaire on a
small number of respondents to check for all previous
issues and potential non-sampling error
• Control on quality parameter (e.g. length and timing of
the questionnaire)
• Better by personal interview (regardless of the actual
survey method, a second pre-testing may be carried out
for some specific administration methods)
• Use a variety of interviewers for personal interviews (to
detect potential interviewer bias)
• Respondent is asked to think aloud
• Debriefing (go through the questionnaire with the
respondent after he has finished to compile it)
• Check consistency with the research objectives
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Indicative costs
Indicative UK costs and response rates for different types of interviews
Variable costs
Survey type
Mail survey
Personal
CAPI
Telephone
CATI
Fixed
costs
2,000
4,000
15,000
4,000
15,000
Total costs
Per respondent
Per
200 respondents 500 respondents 1,000 respondents
questionnaire (assumed response rate)
3
50
60
20
50
15
63
86
40
83
(20)
(80)
(70)
(50)
(60)
5,000
16,500
32,143
12,000
31,667
9,500
35,250
57,857
24,000
56,667
17,000
66,500
100,714
44,000
98,333
Note: costs are in British pounds and are purely indicative, based on 2005 rates of private marketing research
agencies. Fixed costs basically include sampling frame, hiring of equipment and training of interviewers
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Four types of primary surveys
1.
2.
3.
4.
Socio-demographics
Behaviors and economics
Psychographics, lifestyle & attitudes
Response to marketing actions
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Socio-demographic surveys
• Most surveys contain a socio-demographic section to test
relationships between behaviors, attitudes or needs and
belonging to a certain segment of the population
• Socio-demographic information is often used as a
benchmark to test the representativeness of a sample
• Example: the UK Annual Population Survey
• Socio-demographic survey are especially useful to:
monitor demographic trends, gather information on
housing, update information on ageing, monitor
employment, collect information on transport usage,
monitor migration and collect information on minority
groups
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Behavioral and economic surveys
• Monitor consumer purchasing decision and relate behaviors
to their determinants.
• Typical expenditure survey: looks into recorded
expenditures for different products or services, by brand or
category
• Other purchasing decision information may refer to:
• frequency of purchase
• point of purchase
• brand switching.
• Other behavioral surveys:
• Consumption and use
• Disposal
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Attitudinal psychographics and lifestyle
surveys
• Other than economics drivers of behaviors are related to:
•
•
•
•
Lifestyles
Social pressure
Individual attitudes
Habits
• Integration of psychology-based questionnaire sections into
market research surveys
• Example: Ajzen’s theory of planned behavior explains
(intention to) behavior as a function of:
• Attitudes towards behavior (e.g. attitude towards drinking coffee)
• Social norms (e.g. what other people think about drinking coffee)
• Perceived behavioral control (e.g. factors which help or constrain
the choice of drinking coffee)
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Response to marketing actions
• Relation between marketing actions and
consumer response
• Example: advertising has different
objectives
•
•
•
•
Demand increase
Loyalty increase
Product positioning
Defensive strategies against other companies"
action etc.
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Responses to the marketing mix
Marketing mix
Example action
Examples of response variables
Price
Cut prices
Sales, Profits, New customers gained, Market shares,
Perceived quality, Stock reduction
Product
Launch a new product
Consumer acceptance, Brand image effect, Target
customer profile, Price positioning
Promotion
Advertising
Brand/product awareness, Brand loyalty, Brand image,
Sales, Market shares, New customers gained,
Customer retention, Product positioning, Willingness
to pay
Place
Launch e-commerce
New customers gained, Sales, Profits, Brand image,
Market shares
Participants
Improve customer contact management
Customer satisfaction, Brand loyalty, Customer retention,
Perceived quality
Process
Introduce a customer complaining
procedure
Customer satisfaction, Customer retention, Brand loyalty
Physical
evidence
Change selling environment
Consumer acceptance, Sales, New customers gained,
Perceived quality, Willingness to pay, Time spent on
the shop, Customer satisfaction, Brand loyalty
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