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 Planing Start from a problem What is the question? Target group? Data collection Use existing data? Sampling? Check and clean the data Analysis Presentations feedbacks Steps of Statistical analysis

Hibaforrások felméréseknél Construction Validity, specification error Measurement Measurement error Responses Process error Prepared data Analysis Population Target population Covering error Sampling frame Sampling error Sample Nonresponse error Respondents Feldolgozási hiba: könyv, 9999 kód, gépelési hiba, ellentmondó adatok, Tárki 2013 euval nem szimpatizálók aránya Lefedettség: hinyzó egyed, duplikátum, rossz sztártum, többlet, nem cél. Csop tag, csak netes felm. Mintavételi hiba:

Population or sample A 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

Registers List of the individuals For instance Economic units Administrative 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, …

Levels of measurement Categorical Nominal Ordinal Noncategorial, quantitative (metric, scale) Interval Ratio

Nominal Ordinal Interval scale Ratio scale Levels of Measurement Data can be only differentiated Data can be differentiated and arranged Differences can be calculated and are meaningful Differences and ratios can be calculated and are meaningful The choice of a statistical techniuqe is based on the measurement level.

Types of Statistics Descriptive Statistics: Methods of organizing, summarizing, and presenting data in an informative way. Nominal level: tables, graph, mode Ordinal level: tables, graph, mode, median Quantitative 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 Difference Ratio Problems: percent/ percentage point

Aim: Compress the information Tables and charts Aim: Compress the information Tables Charts

Formal requiremets title Units, titles of rows and columns sum Data source notices Order of categories?

Charts Scatter Line Pictogram Cartogram Bar Pie Pictogram Cartogram 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. A bar chart can be used to depict any of the levels of measurement (nominal, ordinal, interval, or ratio).

Data visualization Presentation of data in a pictorial or graphical format.

History

Issues trenDS Small area Vitalize data Correct but understandable charts Suitable charts No redundant information Suitable design New platforms, mobile devices, open source solutions Interactive, real time solutions 3D Geodata New datasources

Line

Radar

Proportional Perceive

Source: http://www.datapine.com/blog/misleading-statistics-and-data/

Pie charts (1) Source: https://en.wikipedia.org/wiki/Misleading_graph In the misleading pie chart, Item C appears to be at least as large as Item A, whereas in actuality, it is less than half as large. Source: https://en.wikipedia.org/wiki/Misleading_graph

pICTOGRAMS Source: https://en.wikipedia.org/wiki/Misleading_graph When using pictograms in bar graphs, they should not be scaled uniformly, as this creates a perceptually misleading comparison.[12] The area of the pictogram is interpreted instead of only its height or width.[13] This causes the scaling to make the difference appear to be squared.[13] In the improperly scaled pictogram bar graph, the image for B is actually 9 times as large as A. Source: https://en.wikipedia.org/wiki/Misleading_graph

Wordcloud   A greedy algorithm is an algorithmic paradigm that follows the problem solving heuristic of making the locally optimal choice at each stage with the hope of finding a global optimum. Illusion preception Source : https://www.visioncritical.com/wp-content/uploads/2012/08/2-the-pros-and-cons-of-word-clouds-as-visualizations.png Source: Steele & Noah: Beautiful Visualization, O Reilly, 2010 Source : https://s-media-cache-ak0.pinimg.com/236x/a7/51/c2/a751c24af03099e6e0c43a28fb23ccaa.jpg