Transcript Multivariate Data Analysis Chapter 1

Quantitative
Research Design
Backdrop to Experimental Design
Quantitative Research Process
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Research Objectives
Background of the Problem
Research Questions
Hypotheses
Method
Data Analysis
Discussions and Implications
Limitations
Research Proposal
A written statement of the research design
 Including the purpose of the study,
definition of the problem, research
methodology and details of the procedures
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Sampling
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Choosing dishes from a buffet
How sampling works (photographic example)
Sampling terminology
 Sample
 Target
population
 Population element
 Census
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Why sample?
 Pragmatic
reasons
 Accurate and reliable results
Populations and Samples
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Population
 A group
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of people that we wish to learn about
Sample
 Group
selected from the population that
participates in the study
Statistics
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Inferential statistics examine likelihood of
differences found in sample to also be
seen in population
 Groups
from same population and differences
due to chance
or
 Groups from different populations
Probability versus
Nonprobability Sampling
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Probability sampling
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Simple random sampling (Each member of population has
an equal chance of being selected)
Systematic sampling
Stratified sampling (Random sample drawn from subgroups)
Proportional versus disproportional strata
Cluster sampling (Sample larger groups, followed by smaller
groupings)
Multistage area sampling
Nonprobability sampling
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Convenience sampling
Judgment sampling (purposive sampling)
Quota sampling
Snowball sampling
Sample Size
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Confidence level
Variables
Categorical (classificatory) variable
 Continuous variable
 Dummy variable
 Independent variable
 Dependent variable
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Tips for Questionnaire Design
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Two basic criteria
 Relevance
 Accuracy
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Opened-ended v.s. fixed-alternative questions
Types of fixed-alternative questions (mutually
exclusive)
 Dichotomous-alternative
question
 Determinant-choice question
 Frequency-determination question
 Checklist question
Basic Question Formats
Various Question Formats
Basic
Question Formats
Open-ended
Questions
Closed-ended
Questions
Scaled
Questions
Basic
Open-ended
Questions
Dichotomous
Questions
Labeled
Questions
Probing
Questions
Multiple-Choice
Responses
Unlabeled
Questions
Clarifying
Questions
Single-coded
Multiple-coded
OPEN-ENDED QUESTIONS: Questions to which
respondents give their responses freely, according to
their own will.
Basic Open Ended Questions.
Q. What do you particularly like about Lipton Tea?
______________________________________________________________________________
Q. Why are you unwilling to buy a cellular phone when it is available in the market?
________________________________________________________________________
Probing Questions
Q. What do you particularly like about Johnson & Johnson baby oil?
__________________________________________________________________________
PROBE: Anything else?
Advantages and disadvantages of
Open-ended Questions
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Advantages
Since they do not restrict the
respondent’s response, the
widest scope of response can
be attained.
Most appropriate where the
range of possible responses
is broad, or cannot be
predetermined.
Less subject to interviewer
bias.
Responses may often be used
as direct quotes to bring
realism and life to the written
report.
Disadvantages
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Inappropriate for self-administered
questionnaire since people tend to
write more briefly than they speak.
The interviewer may only record a
summary of the responses given
by an interview and fail to capture
the the interviewer’s own ideas.
It is difficult to categorize and
summarize the diverse responses
of different respondents.
May annoy a respondent and
prompt him/her to terminate the
interview, or ignore the mail
questionnaire.
CLOSED-ENDED QUESTIONS: Questions to which
respondents are required to answer from set of alternative
responses provided by the researcher. Could be dichotomous or
multiple choice.
Dichotomous Questions With No Neutral Response
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Q.Do you have a cellular phone?
Yes ...................................... 1 without neutral
No ...................................... 2 response
Dichotomous Questions With Neutral Response
Q.Is it likely that you will purchase a cellular phone in the next
six months?
Yes ...................................... 1 with neutral
No ...................................... 2 response
Not Sure .............................. 3
Single- and multi-coded multiple choice questions
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Q. On an average, how much do you spend on newspapers, books and magazines in a
month? (Please check one from the following responses.)
Less than $15 ...................................
Between $16 & $30 ......................….
Between $31 & $45 .......................…
Between $46 & $60 .....................…..
$60 or more .................................…..
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Single-coded
question
Q. Which of the following household appliances does your household have?
(Please check as many responses that are applicable to you.)
TV
LCD
PC
Fax
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…………4
VCR
…… … 5
Microwave
….…… 6
Cellular phone ……….7
Others
……….8
Specify ____________
Multi-coded
question
__________________________________________________________________________________________________
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Advantages and Disadvantages of
Closed-ended Questions
ADVANTAGES
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All respondents reply on a
standard response set. This
ensures comparability of
responses, facilitates
coding, tabulating and
interpreting the data.
Easier to administer and
most suited for selfadministered questionnaire.
If used in interviews, less
skilled interviewer may be
engaged to do the job.
DISADVANTAGES
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Preparing the list of
responses is timeconsuming.
If the list of responses
is long, the
respondents may be
confused.
If the list of responses
is not comprehensive,
responses may often
fail to represent the
respondent’s point of
Scaling questions
 Scaling questions are special types of closed-ended questions.
 They include, among others, the following categories of questions.
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Behavioral/Attitudinal questions
Buying-intent questions
Agree-Disagree questions
Preference questions
Ranking questions
Semantic differential questions
Constant-sum questions
 The questions can be labeled or unlabeled
Labeled and Unlabeled Scaling Questions
Type of
Scaled
Questions
Unlabeled
scaledresponse
question
Labeled
scaledresponse
question
Examples
“On a scale of 1 to 7,
how would you rate
the IBM Thinkpad on
ease of operation?
Advantages
1. Allows a respondent to
express the degree of
his/her intensity of
feelings.
2. Easy to administer and
code.
“Do you disagree
1. Allows a respondent to
strongly, disagree,
express the degree of
agree, or agree strongly his/her intensity of
with the statement,
feelings.
‘IBM laptops are a
2. Easy to administer and
better value than
code.
Compaq laptops’?”
3. Respondents can relate
to the scale.
Disadvantages
Respondents
may not relate to
the scale well.
Scale may be
“forced” or
overly detailed.
Considerations in choosing a question format
• Nature of the property being measured
– Subjective Vs objective
• Previous research studies
– Need for comparison with past studies
• Data Collection Mode
– Telephone/face-to-face-interview/mail
• Scale level desired
– Statistical analysis
• Ability of the respondents
Phrasing and Sequencing of Questions
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PHRASING
Focus on a single
issue or topic
Ask precise
questions using
respondent’s core
vocabulary
Avoid
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use of vague words
asking leading or
loaded questions
estimation questions
double barreled
questions
presumptuous
questions
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SEQUENCING
Start with simple opening
questions
Place
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broad-based questions
first;
more specific and
narrow questions and
difficult, sensitive,
embarrassing questions
should come
later(Funnel approach)
Classification questions
last.
Transition from one topic
to another should be
smooth
Questionnaire Layout
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Provide sufficient spaces
Use prominent print for instructions
Use filtered questions
Do not slit the same question over two
pages
• Number the questions
• Layout should facilitate editing and
coding
The Art of Asking Questions
Avoid complexity: use simple language
 Avoid leading and loaded questions
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 Counterbiasing
statement
 Split-ballot technique
Avoid ambiguity: be as specific as possible
 Avoid double-barreled items
 Avoid making assumptions
 Avoid burdensome questions that may tax
the respondent’s memory
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Some Issues about Questionnaire
Design
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Order Bias
 Funnel
technique
 Anchoring effect
 Filter question
 Pivot question
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Best Layout
 Multiple-grid
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question
Pre-testing and Revising
Survey Research
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Advantages of survey research:
 Quick
 Inexpensive
 Efficient
 Accurate
Survey Research
Nonresponse
error
Random
sampling
error
Respondent
error
Acquiescence
bias
Deliberate
falsification
Response
bias
Total Error
Interviewer bias
Unconscious
misrepresentation
Systematic
error
Data processing error
Administrator
error
Extremity bias
Sample selection error
Interviewer error
Interviewer cheating
Auspices bias
Social
desirability
bias
Experimental Research
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A research investigation in which conditions
are controlled so that an independent
variable(s) can be manipulated to test a
hypothesis about a dependent variable.
Allows evaluation of causal relationships
among variables while all other variables are
eliminated or controlled.
Summary
Survey is a quantitative research tool
because it can be quick, inexpensive,
efficient, and accurate.
 It’s important to reduce different types of
errors during the survey.
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