Description of Statistics

Origin : - The word, 'statistics' has been derived from the Latin word 'Status', Italian word 'Statista', German word 'Statistik' and French word 'Statistique' which means political state.
Statistics, as an instrument of collection of data was used for the first time in Egypt in conducting census of population and wealth for raising the pyramids in 3050 B.C.
In india the use of of statistics seems to have begun from the period of Chandragupta Maurya with the collection of vital statistics and introduction of the registration of births and deaths. Akbari and Kautilya's Arthasastra provide evidence to the fact that statistics was very much used in India during the region of emperor Akbar and Chandragupta for the administration and manoeuvrings wars.

Statistics is defined as the collection, presentation, analysis and interpretation of numerical data.
According to this definition, there are five stages.
1. Collection of data: There are various methods for collecting the data such as census, sampling, primary and secondary data etc.
2. Organization of data: After collection, the data are organized in a proper form which involves editing, classification and tabulation.
3. Presentation of data: After classification the data are presented in some suitable manner either in a diagrammatic or graphical manner.
4. Analysis of data: Simple mathematical techniques are applied in analysis. Analysis includes condensation, summarization, conclusion, etc., through the means of measures of central tendencies, dispersion, skewness, kurtosis, correlation, regression, etc.
5. Interpretation of data. Interpretation is the last step. To derive meaning conclusions from analyzed data is called interpretation of data. It involves statistical thinking, skill and experience.
Statistics has been defined variously by various authors in two different senses namely plural and singular. In the plural sense, it has been defined as a number of data and in the singular sense it has been defined as a method applied to the data.
Types of data with reference to collection: There are two types of data.
1. Primary data: Primary data are those data which are obtained for the first time by the investigator himself. In other words, “The data originally obtained in the process of investigation are known as primary data.”
2. Secondary data: Secondary data are those data which have already been collected by some other persons for their purpose. That is, the data taken from published or unpublished records like, research papers, news papers, periodicals, journals, office records, etc, are known as secondary data.
Methods of collection primary data:
1. Direct personal investigation: In this method, the investigator interviews the respondents personally. That is investigator establishes personal contact with the respondents and conducts on the spot enquiry and puts simple and direct question to them.
i) The success of this method depends upon the character and efficiency of the investigator.
ii) The result of this method is more reliable and correct information.
2. Indirect oral investigation: In this method, this method is also called indirect personal Investigation or Interviews. In this method, the investigator contacts third parties capable of supplying the necessary information of the problem under investigation. Such persons are known as witness.
3. Information through local sources or correspondents: This method is also known as ‘information though local agencies’. In this method information is collected though the local sources, agents or correspondents on request.
4. Data through Questionnaire: A questionnaire consisting of a list of questions pertaining to the investigation is prepared and printed in advance. The questionnaires are containing blank spaces for answers. This questionnaire is filled by the respondent.
If the questionnaires are sent by post to the informants who are requested to write the answers in the blank spaces and send back within a specified time, then this method is known as ‘Mailed Questionnaire Method’.
5. Data through Schedules: This method is also called ‘Questionnaire in-charge of enumerators’. The Schedule is filled by the interviewer.
Methods of collecting Secondary Data:
1. Information collected though newspapers and periodicals.
2. Information obtained from the publications of trade associations.
3. Information obtained from the research papers published by University departments.
4. Information obtained from the official publication of the central, state and the local governments dealing with crop statistics, industrial statistics, trade and transport statistics etc.
5. Information obtained from the official publication of the foreign governments for international organizations.
Types of classification of data:
There are four type of classification of data.
1. Geographical / Spatial Series data: Classification on the basis of place is called geographical classification. In this, data are classified according to different areas like, states, district, towns, villages, etc.
2. Chronological /temporal series data: Classification on the basis of time periods (year, months, weeks, days, hours etc) is called chronological classification.
3. Qualitative classification: Classification based on the presence or absence of an attribute is known as qualitative classification.
4. Quantitative classification: Classification on the basis of measurable characteristics of the units under study is said to be quantitative classification or classification according to variable.
Type of Presentation
There are three types of presentation available.
1. Text Presentation: In this method of data presentation the data are shown by combining together text and figures.
2. Tabular presentation: Tabulation is systematic presentation of data with help of a statically table having a number of rows and columns and complete with reference to number, title, description of rows and columns and foot note if any.
Main Parts of Table:
i) Table number: A table should be numbered for identification. The number may be put at the center, above the title or at the bottom of the table.
ii) Title of the table: It should be clear, brief and self explanatory.
iii) Date:
iv) Head Note: This is always placed below the tile. It is a statement to explain the contents of the table.
v) Body of the table: It consists of data and figures. There should be proper arrangement of items in columns and rows and irrelevant matter should be excluded.
vi) Stubs: each row of the table mush has a heading. The designations of the rows are called stubs.
vii) Captions: A table has many columns. Sub-headings of the columns are called captions or headings.
viii) Unit of measurement: The units of measurements of the figures in a column or a row of the table mush be given fully and accurately.
ix) Source Note: If data is collected though some secondary sources a note must be made below the table regarding the sources from with the data has been collected.
x) Foot note: This is used to explain the things that may not be clear in the main body.

3. Diagrammatic Presentation: Presentation with help of charts, pictures and diagrams.
(i) Line diagram
(ii) Bar Diagram
a) Simple bar b) Multiple Bar c) Subdivided Bar d) Subdivided Bar with %
(iii) Pie Chart
Graphs:
i) Histogram ii) Frequency polygon iii) Frequency Curves iv) Ogive
Limitation of statistics
1. Statistics deals only with aggregates.
2. Statistics is concerned with quantitative data and not qualitative phenomena.
3. Statistics are always numerically expressed.
4. Statistics should be estimated.
5. The laws of statistics are not exact.