Role of Data in Decision Making
29-06-2023
Role of Data in Decision Making
DATA & INFORMATION
In God we trust, all others must bring data
- W Edwards Deming
Dr. Kiran K
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Role of Data in Decision Making
29-06-2023
London Cholera Outbreak - 1854
Severe outbreak of cholera that occurred near Broad Street (now
Broadwick street) in Soho district of London in 1854.
More than 500 people died within 10 days of the outbreak, the
mortality rate in some parts of the city was as high as 12.8%.
Dr. Kiran K
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Role of Data in Decision Making
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May 2020
Dr. Kiran K
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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Role of Data in Decision Making
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DATA TYPE
Data Level
Meaningful Operations
Nominal
Classifying and Counting
Ordinal
All of the above plus Ranking
Interval
All of the above plus Addition,
Subtraction, Multiplication, and
Division (including means, standard
deviations, etc.)
Ratio
All of the above
Qualitative/Categories
(No Ordering or direction)
Ranking, Order, Scaling
Differences between measurements
(no true zero)
Differences between measurements &
true zero exists
DATA TYPE
Dr. Kiran K
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Role of Data in Decision Making
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DATA TYPE
DIVISIONS /
DEPARTMENTS
STAKEHOLDERS
Manufacturing
/ Operations
Finance
Marketing
COMPANY
Human Resource
Legal
DECISIONS
Dr. Kiran K
Research &
Development
DATA
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Role of Data in Decision Making
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DATA STRUCTURING
• Classification
• 1 dimension / variable / Univariate
• Tabulation
• More than 1 variable
• Simultaneous representation
DATA STRUCTURING
• Classification
• 1 dimension / variable / Univariate
• Discrete
Dr. Kiran K
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Role of Data in Decision Making
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DATA STRUCTURING
• Classification
• 1 dimension / variable / Univariate
• Continuous
Ungrouped Versus Grouped Data
• Ungrouped data
• have not been summarized in any way
• are also called raw data
• Grouped data
• logical groupings of data exists
• i.e. age ranges (20-29, 30-39, etc.)
• have been organized into a frequency distribution
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Role of Data in Decision Making
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Example of Ungrouped Data
42
26
32
34
57
30
58
37
50
30
53
40
30
47
49
50
40
32
31
40
52
28
23
35
25
30
36
32
26
50
55
30
58
64
52
49
33
43
46
32
61
31
30
40
60
74
37
29
43
54
Ages of a Sample of
Managers from
Urban Child Care
Centers in the
United States
Frequency Distribution
• Frequency Distribution – summary of data presented in the form of class
intervals and frequencies
• Vary in shape and design
• Constructed according to the individual researcher's preferences
• Discrete
• Continuous
Dr. Kiran K
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Role of Data in Decision Making
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Frequency Distribution of Child Care Manager’s Ages
Class Interval
20-under 30
30-under 40
40-under 50
50-under 60
60-under 70
70-under 80
Frequency
6
18
11
11
3
1
Common Statistical Graphs – Quantitative Data
• Histogram -- vertical bar chart of frequencies
• Frequency Polygon -- line graph of frequencies
• Ogive -- line graph of cumulative frequencies
• Stem and Leaf Plot – Like a histogram, but shows individual data values.
Useful for small data sets.
• Pareto Chart -- type of chart which contains both bars and a line graph.
• The bars display the values in descending order, and the line graph shows the
cumulative totals of each category, left to right.
• The purpose is to highlight the most important among a (typically large) set of
factors.
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Role of Data in Decision Making
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Histogram
• A histogram is a graphical summary of a frequency
distribution
• The number and location of bins (bars) should be
determined based on the sample size and the range of the
data
10
0
Frequency
Class Interval Frequency
20-under 30
6
30-under 40
18
40-under 50
11
50-under 60
11
60-under 70
3
70-under 80
1
20
Histogram
0
10 20 30 40 50 60 70 80
Years
Dr. Kiran K
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Role of Data in Decision Making
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10
0
Frequency
6
18
11
11
3
1
Frequency
Class Interval
20-under 30
30-under 40
40-under 50
50-under 60
60-under 70
70-under 80
20
Frequency Polygon
0
10 20 30 40 50 60 70 80
Years
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Frequency
20
0
Class Interval
20-under 30
30-under 40
40-under 50
50-under 60
60-under 70
70-under 80
Cumulative
Frequency
6
24
35
46
49
50
60
Ogive
0
10
20
30
40
50
60
70
80
Years
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Role of Data in Decision Making
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Relative Frequency Ogive
Class Interval
20-under 30
30-under 40
40-under 50
50-under 60
60-under 70
70-under 80
Cumulative Relative Frequency
Cumulative
Relative
Frequency
.12
.48
.70
.92
.98
1.00
1.10
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
0
10
20
30
40
50
60
70
80
Years
Stem and Leaf plot:
Safety Examination Scores for Plant Trainees
Raw Data
Dr. Kiran K
Stem
Leaf
86
77
91
60
55
2
3
76
92
47
88
67
3
9
23
59
72
75
83
4
79
77
68
82
97
89
5
569
6
07788
81
75
74
39
67
7
0245567789
79
83
70
78
91
8
11233689
68
49
56
94
81
9
11247
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Role of Data in Decision Making
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Construction of Stem and Leaf Plot
Raw Data
Stem
86
77
91
60
76
92
47
88
23
59
72
75
83
77
68
82
97
89
81
75
74
39
67
79
83
70
78
91
68
49
56
Leaf94
81
Stem
Leaf
55
2
3
67
3
9
4
79
5
569
6
07788
7
0245567789
8
11233689
9
11247
Stem
Leaf
Histogram vs. Stem and Leaf?
• So, which one should I use?
• A Stem and Leaf plot is useful for small data sets. It
shows the values of the datapoints.
• A histogram foregoes seeing the individual values of
the data for the bigger picture of the distribution of
the data
• The purpose of these graphs is to summarize a set of
data. As long as that need is met, either one is okay to
use.
Dr. Kiran K
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Role of Data in Decision Making
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Common Statistical Graphs – Qualitative Data
• Pie Chart -- proportional representation for categories
of a whole
• Bar Chart – frequency or relative frequency of one
more categorical variables
Frequency
Pareto Chart
100
100%
90
90%
80
80%
70
70%
60
60%
50
50%
40
40%
30
30%
20
20%
10
0
10%
0%
Poor
Wiring
Dr. Kiran K
Short in
Coil
Defective
Plug
Other
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