business research methods william g. zikmund chapter 20: basic data analysis: descriptive statistics
TRANSCRIPT
BusinessResearch Methods
William G. Zikmund
Chapter 20:
Basic Data Analysis: Descriptive Statistics
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Descriptive analysis
• The transformation of raw data into a form that will make them easy to understand and interpret; rearranging, ordering, and manipulating data to generate descriptive information.
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Type ofMeasurement
Nominal
Twocategories
More thantwo categories
Frequency tableProportion (percentage)
Frequency tableCategory proportions
(percentages)Mode
Type of descriptive analysis
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Type ofMeasurement
Type of descriptive analysis
Ordinal Rank orderMedian
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Type ofMeasurement
Type of descriptive analysis
Interval Arithmetic mean
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Type ofMeasurement
Type of descriptive analysis
RatioIndex numbers
Geometric meanHarmonic mean
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Tabulation
• Tabulation - Orderly arrangement of data in a table or other summary format
• FREQUENCY TABLE
• PERCENTAGES
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Frequency table
• The arrangement of statistical data in a row-and-column format that exhibits the count of responses or observations for each category assigned to a variable.
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Measure ofCentral Measure of
Type of Scale Tendency Dispersion
Nominal Mode NoneOrdinal Median PercentileInterval or ratio Mean Standard deviation
CENTRAL TENDENCY
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Cross-tabulation
• A technique for organizing data by groups, categories, or classes, thus facilitating comparisons; a joint frequency distribution of observations on two or more sets of variables.
• Contingency table- The results of a cross-tabulation of two variables, such as survey questions.
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CROSS-TABULATION
• ANALYZE DATA BY GROUPS OR CATEGORIES
• COMPARE DIFFERENCES
• CONTINGENCY TABLE
• PERCENTAGE CROSS-TABULATIONS
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Base
• The number of respondents or observations (in a row or column) used as a basis for computing percentages.
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ELABORATION AND REFINEMENT
• MODERATOR VARIABLE– A third variable that, when introduced into an
analysis, alters or has a contingent effect on the relationship between an independent variable and a dependent variable.
– SPURIOUS RELATIONSHIP– An apparent relationship between two variables
that is not authentic.
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QUADRANT ANALYSIS
TwoTworatingratingscalesscales
4 quadrants4 quadrantstwo-dimensionaltwo-dimensional
tabletable Importance-Importance-PerformancePerformance
Analysis)Analysis)
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DATA TRANSFORMATION
• DATA CONVERSION
• CHANGING THE ORIGINAL FORM OF THE DATA TO A NEW FORMAT
• MORE APPROPRIATE DATA ANALYSIS
• NEW VARIABLES
DATA TRANSFORMATION
SUMMATIVE SCORE =
VAR1 + VAR2 + VAR 3
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COLLAPSING A FIVE POINT SCALE
• STRONGLY AGREE• AGREE• NEITHER AGREE
OR DISAGREE• DISAGREE• STRONGLY
DISAGREE
• STRONGLY AGREE/AGREE
• NEITHER AGREE OR DISAGREE
• DISAGREE/ STRONGLY DISAGREE
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INDEX NUMBERS
• Score or observation recalibrated to indicate how it relates to a base number
• CPI - Consumer Price Index
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CALCULATING RANK ORDER
• ORDINAL DATA
• BRAND PREFERENCES
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TABLES
• BANNERHEADS FOR COLUMNS
• STUDHEADS FOR ROWS
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CHARTS AND GRAPHS
• PIE CHARTS
• LINE GRAPHS
• BAR CHARTS– VERTICAL– HORIZONTAL
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0
20
40
60
80
100
1st
Qtr
2nd
Qtr
3rd
Qtr
4th
Qtr
East
West
North
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COMPUTER PROGRAMS
• SPSS
• SAS
• SYSTAT
• MICROSOFT EXCEL
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COMPUTER PROGRAMS
• Box and Whisker Plots
• Interquartile range - midspread
• Outlier
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Interpretation
• the process of making pertinent inferences and drawing conclusions
• concerning the meaning and implications of a research investigation