statistics i.. course materials lecture notes coospace
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Statistics I.
Course materials
Lecture notes
Coospace
http://www2.eco.u-szeged.hu/stat/
Parts of Exam
Seminar: 2 computer based test
Colloquium Written exam in two parts
Introductions, notes
Statistics and other subjectsIT and StatisticsHow can you learn?Interactive lessons
Aims
Improve your statistical literacyIn the case of a given problem
Identify the applicability of statistics as a way of solution
Identify the applicable statistical methods
Interpretation of the data and results
Topics Semester 1 Descriptive statistics Comparison of data Time series
Semester 2 Inferential statistics
Hypothesis, regression, etc.
Basic terms
What are the aims and objects of statistics?Where can we encounter in statistics?What is the importance of statistics?
Who Uses Statistics?
Statistical techniques are used extensively by marketing, accounting, quality control, consumers, professional sports people, hospital administrators, educators, politicians, physicians, etc...
What is Meant by Statistics?
Statistics is the science of collecting, organizing, presenting, analyzing, and interpreting numerical data to assist in making more effective decisions.
Examination of mass phenomenon
Steps of Statistical analysis
Population or sampleA population is a collection of all possible individuals, objects, or measurements of interest.
A sample is a portion, or part, of the population of interest
registersList of the individuals
For instance
Economic unitsAdministrative units
Properties of the individuals: variables
- What is the codomain?
•For example:• Gender: male or female
• weight• 1,2,3,…,50,….kg• -10; 11-20; 21-30, …
Summary of Types of Variables
C h a rt T it le
Q u a lita tive o r a ttrib u te o r ca te g orica l(typ e o f ca r o w n e d)
d isc re te(n u m b e r o f ch ild re n)
co n tin uo us(tim e ta ke n fo r an e xa m )
Q u a ntita tive o r n u m e rica l
D A T A
Levels of measurement
Categorical Nominal Ordinal
Noncategorial, quantitative (metric, scale) Interval Ratio
Levels of Measurement
Nominal level: Data that is classified into categories and cannot be arranged in any particular order.
EXAMPLES: eye color, gender, religious affiliation.
Levels of MeasurementOrdinal level: involves data arranged in some order, but the differences between data values cannot be determined or are meaningless.
EXAMPLE: During a taste test of 4 soft drinks, Mellow Yellow was ranked number 1, Sprite number 2, Seven-up number 3, and Orange Crush number 4.
Levels of MeasurementInterval level: similar to the ordinal level, with the additional property that meaningful amounts of differences between data values can be determined. There is no natural zero point.
EXAMPLE: Temperature on the Fahrenheit scale.
Levels of Measurement
Ratio level: the interval level with an inherent zero starting point. Differences and ratios are meaningful for this level of measurement.
EXAMPLES: Monthly income of surgeons, or distance traveled by manufacturer’s representatives per month.
Types of StatisticsDescriptive Statistics: Methods of organizing, summarizing, and presenting data in an informative way.
Nominal level: tables, graph, modeOrdinak level: tables, graph, mode, medianQuantitative variable: tables, graphs, mode, median, mean, dispersion, skewness
Types of Statistics
Inferential Statistics: A decision, estimate, prediction, or generalization about a population, based on a sample.
Comparison of data
DifferenceRatio
Problems: percent/ percentage point
Tables and chartsAim: Compress the information
1. Tables
2. Charts
Formal requiremets
titleUnits, titles of rows and columnssumData sourcenotices
Order of categories?
Charts
• Scatter• Line
• Bar• Pie• Pictogram• Cartogram
Scatter
Forrás: saját szerkesztés
Line
Radius Eljárás innovációt folytató vállalkozások körében az innováció típusok aránya a különböző nemzetgazdasági ágakban, 2008
Forrás: KSH adatok alapján saját szerkesztés
Bar Chart
A bar chart can be used to depict any of the levels of measurement (nominal, ordinal, interval, or ratio).
Example3EXAMPLE 3: Construct a bar chart for the number of unemployed per 100,000 population for selected cities during 2001 City Number of unemployed
per 100,000 population Atlanta, GA 7300 Boston, MA 5400 Chicago, IL 6700
Los Angeles, CA 8900 New York, NY 8200
Washington, D.C. 8900
Bar Chart for the Unemployment Data
7300
54006700
89008200
8900
0
2000
4000
6000
8000
10000
1 2 3 4 5 6
Cities
# u
nem
plo
yed
/100
,000
Atlanta
Boston
Chicago
Los Angeles
New York
Washington
Pie Chart
A pie chart is useful for displaying a relative frequency distribution. A circle is divided proportionally to the relative frequency and portions of the circle are allocated for the different groups.
EXAMPLE 4 continued
Type of shoe # of runners
Nike 92
Adidas 49
Reebok 37
Asics 13
Other 9
EXAMPLE 4: A sample of 200 runners were asked to indicate their favorite type of running shoe. Draw a pie chart based on the following information.
Pie Chart for Running Shoes
Nike
Adidas
ReebokAsics
Other
Nike
Adidas
Reebok
Asics
Other
Pictogram
1 unit=1000 pigs
Pigs in a farm(2011)
Cartogram
Forrás: OMSZ
Heatmap of Hungary (2010.09.02. 14:00) °C
Forrás: Eurostat