materials developed under the european programme: data analysis
TRANSCRIPT
Materials developed under the European programme:
DATA ANALYSIS
“There are three kinds of lies:
lies,
damned lies
and Statictics”B. Disraeli
STATISTICS
MARKETING
RESEARCH
PRODUCTION
MEDICINE
POLITICS
SPORT
Structure of Statistics Research
Define problem
Collectdata Carry out
analysis Make conclusions
STATISTICS VARIABLES
measureable non-measureable
continuous discrete quasi-discrete
May have
many values
Limited number of values, not very numerous
Limited number of values, very numerous
Cannot be presented in numbers
• number of children in family
• education
• weight of 1 package of washing powder
• number of exams in one session
• surface of apartment
• voting preferences
• tax paid for year 1999
• number of goals in football match
• time of getting to work
• number of pages in statistics’ book
What type of variable is this one? no
n-m
easu
able
con
tinu
ous
quas
i-di
scre
te
disc
rete
POPULATION (N)
SAMPLE (n)
We are politically correct – sample must be representative !!!
Simple series
Examing feature: Age
22 1725
37
56
23 22 26
25
31 30
35
32
24
40
23
7218
30
40
Answers put in order increasingly or dicreasingly.
17, 18, 22, 22, 23, 23, 24, 25, 25, 26, 30, 30, 31, 32, 35, 37, 40, 40, 56, 72
Variable: all types
Range series
Examing feature: Age
5672
1718
22252322 262530 24 2330
3731 353240 40
Answers seperated in ranges.
Variable: continuous and quasi-continuous
From - To
Below age 20
20 - 30
30 - 40
Over 40 age
Numerousity
2
10
6
2
Range series
Examing feature: Age
Variable: continuous and quasi-continuous
From - To
xd - xg
Below 20
20 - 30
30 - 40
Over 40
Numerousity
fi
2
10
6
2
Structure index
wi
Accumulated numerousity
fisk
Accumulated structure index
wisk
10%
50%
30%
10%
2
12
18
20
10%
60%
90%
100%
Weighed series
Examing feature: Number of rooms
44
11 1 1
22
1
22 2 22
33
4
33 3
Answers selected into classes
Variable: discrete
Value
1
2
3
4
Numerousity
5
7
5
3
Punctuation series
Examing feature: Number of roomsVariable: discrete
Value
xi
1
2
3
4
Numerousity
fi
5
7
5
3
Structure index
wi
Accumulated numerousity
fisk
Accumulated structure index
wisk
Histogram
Numerousity and accumulated numerousity
Line plotAge
0
5
10
15
Below 20 20 - 30 30 - 40 Over 40
Age
0
5
10
15
20
25
Below 20 20 - 30 30 - 40 Over 40
Age
0
5
10
15
Below 20 20 - 30 30 - 40 Over 40
Age
0
5
10
15
20
25
Below 20 20 - 30 30 - 40 Over 40
Variable: continuous and quasi-continuous
Numerousity diagram
Variable: discrete
Numerousity and accumulated numerousity
Number of rooms in apartment
02468
0 1 2 3 4
rooms
Number of rooms in apartment
0
10
20
30
0 1 2 3 4
rooms
Pie chart
Variable: all types
Structure index
Number of rooms in apartment
25%
35%
25%
15%
1 room
2 rooms
3 rooms
4 rooms