Transcript Chapter 15

Basic Data Analysis:
Descriptive Statistics
Coding Data and the Data Code
Book
• Data entry refers to the creation of a
computer file that holds the raw data
taken from all of the questionnaires
deemed suitable for analysis
• Data coding refers to the identification
of codes that pertain to the possible
responses for each question on the
questionnaire
• Data code book identifies all of the
variable names and code numbers
associated with each possible
response
to
each
question
that
makes
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up the data set
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Types of Statistical Analyses
Used in Marketing Research
• Data summarization: the process of
describing a data matrix by
computing a small number of
measures that characterize the data
set
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Types of Statistical Analyses
Used in Marketing Research
• Four functions of data summarization:
– Summarizes the data
– Applies understandable
conceptualizations
– Communicates underlying patterns
– Generalizes sample findings to the
population
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Why is Statistical Analysis
Used?
• Why Use Statistical Analysis?
– To summarize data
• The average price of a Gateway PC
is $2,489
• The low is $999, and the high is
$4,678: this is the range
• The mode is $2,200
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Why is Statistical Analysis
Used?
• Why Use Statistical Analysis?
– To show basic patterns in the data
• 30% buys at $1,500 or less
• 50% buys at between $2,500 and
$1,500
• 20% buys at $2,500 or more
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Why is Statistical Analysis
Used?
• Why Use Statistical Analysis?
– To interpret these patterns
• The majority of Gateway buyers pay
$2,500 or less
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Why is Statistical Analysis
Used?
• Why Use Statistical Analysis?
– To generalize the patterns to the
population
• 95% of all Gateway buyers pay
between $2,000 and $3,000 for their
PC’s
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Types of Statistical Analyses
Used in Marketing Research
• Statistical Analysis:
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Types of Statistical Analyses
Used in Marketing Research
•
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Five Types of Statistical Analysis:
1. Descriptive analysis: used to
describe the data set
2. Inferential analysis: used to
generate conclusions about the
population’s characteristics based
on the sample data
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Types of Statistical Analyses
Used in Marketing Research
3. Differences analysis: used to
compare the mean of the
responses of one group to that of
another group
4. Associative analysis: determines
the strength and direction of
relationships between two or
more variables
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Types of Statistical Analyses
Used in Marketing Research
5. Predictive analysis: allows one to
make forecasts for future events
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Understanding Data Via
Descriptive Analysis
• Two sets of descriptive measures:
– Measures of central tendency:
used to report a single piece of
information that describes the most
typical response to a question
– Measures of variability: used to
reveal the typical difference
between the values in a set of
values
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Understanding Data Via
Descriptive Analysis
• Measures of Central Tendency:
– Mode: the value in a string of numbers
that occurs most often
– Median: the value whose occurrence lies
in the middle of a set of ordered values
– Mean: sometimes referred to as the
“arithmetic mean”; the average value
characterizing a set of numbers
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Understanding Data Via
Descriptive Analysis
• Measures of Variability:
– Frequency distribution reveals the
number (percent) of occurrences of each
number or set of numbers
– Range identifies the maximum and
minimum values in a set of numbers
– Standard deviation indicates the degree
of variation in a way that can be
translated into a bell-shaped
curve distribution
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Understanding Data Via
Descriptive Analysis
• Measures of Variability:
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When to Use a Particular
Statistic
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