data 1
Basic analysis
Essentially summarizes and communicates patterns found in the data sets
Before data can be analyzed: data entry stage
the creation of a computer file that holds raw data
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Data coding
Assigning codes to the possible responses for each question
typically codes are numerical
in large projects, a data code book may be used
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Data matrix
The coded raw data from the survey
columns: represent answers to the questions
rows: represent each respondent or case
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Data reduction
Marketing researcher faces problem of data reductionwhen confronting a data matrix.
How do I condense the data matrix into a few representative measures which can help me
summarize the data and convey their salient characteristics?
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What data reduction accomplishes
Summarizes the data
Applies understandable conceptualizations
Communicates underlying patterns
Generalizes sample findings to the population
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Types of statistical analysis used in marketing research
1. Descriptive analysis
2. Inferential analysis
3. Differences analysis
4. Associative analysis
5. Predictive analysis
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1. Descriptive analysis
Used to describe the data set in a way that a "typical" respondent would respond, reveals the
general pattern of responses
techniques: mean, median, mode, standard deviation, range
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2. Inferential analysis
Used to generate conclusions about the populations characteristics based on the sample data
techniques: hypothesis testing: estimating true population values based on sample info
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3. Difference analysis
Used to test the difference between or among groups
techniques: t-test for significant differences, analysis of variance (ANOVA)
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4. Associative analysis
Used to determine systematic among relationships variables including if and how two variables are
related
techniques: cross-tabulations and correlations
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5. Predictive analysis
Used to help the marketing researcher make predictions or forecasts about future events
techniques: regression analysis, time series analysis
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Measures of central tendency
Goal: to report a single piece of information that describes the most typical response to a given
question
mean, median, mode
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Mode
The value in a string of numbers that occurs MOST often
used with nominal scales
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Median
Expresses the value that lies in the middle of an ordered set of values
used with ordinal scales
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Mean
The average value characterizing a set of numbers
used with interval and ratio scales
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Measures of variability
Depict the "typical" difference between the values in a set of values
frequency/percentage distribution, cumulative percentage distribution, standard deviation,
range
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Frequency/percentage distribution
A tabulation of the number of times that each value appears in a particular set of values
often represented by bar charts
used with nominal scales
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Range
Identifies the distance between the minimum and the maximum value in an ordered set of values
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Standard deviation
The SD indicates the degree of variation in the values translated into a normal distribution
SD are standardized units that express how much of the area under the curve lies within the
limits expressed:
+/- 1.96 SD = 95%
+/- 2.58 SD = 99%
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When to use a particular descriptive measure for each type of scale
Type of scale
Nominal: Mode, frequency distribution
Ordinal: Median, cumulative percentage distribution
Interval/ratio: Mean, SD, range