Description of statistical data

                 DESCRIPTION OF STATISTICAL DATA

STATISTICS: It is a scientific method or subject consisting of principles, methods and techniques for collection, presentation, analysis and interpretation of data.

OBJECTIVES OF STATISTICS: The main objectives of statistics are:

The collection of necessary data.

Systematic presentation of collected data.

Analysis of data for the required purpose.

Interpretation of the results based on the analysis.

DATA: The set of figures or facts collected relating to one or more characteristics under consideration.

Ex: The following data represents the marks obtained by a group of students in a particular subject.

40, 35, 76,97,92,84 etc.

TYPES OF DATA: Based on the collection, the data is divided into two types.

1) Primary Data     2) Secondary Data

PRIMARY DATA: The data which is collected by the investigator directly for his study is referred as primary data.

It is first hand data, and generally the information obtained by this data is more reliable and accurate.

COLLECTION OF PRIMARY DATA: The primary data can be computed using the following important methods.

1) OBSERVATION METHOD:  In this method the investigator can collect the data by observing the situation personally.

Ex:

 a) To know the behaviour or character of a person.

 b)  Measuring the height of group of people.

2) INTERVIEW METHOD: In this method the investigator collects the data by interacting the people. It is mainly divided into two types.

DIRECT PERSONAL INTERVIEW: Under this method the information collected by the investigator through personal from the respondent. The reliability of collecting data depends upon the training & attitude of the investigator. This method is most suitable for the type of investigation where it is confidential & the process of investigation is so complex & requires personal attention of the investigator.

ADVANTAGES:

Ø  It is possible to collect original, accurate & exact data.

Ø  The doubts of the respondent can be clarified.

DISADVANTAGES:

Ø  This method involves more time & money.

Ø  Skilled enumerators are required to collect the data.

INDIRECT PERSONAL INTERVIEW: This method is used when the respondent are not reliable & interested to provide the information directly. It is also useful to collect the information secretly.

Ex: This method is adopted by various people to collect the data regarding enquires & investigations.

DISADVANTAGES: The information collected from different persons may not be same & comparable. The data may be biased as it is provided by the third person.

3) MAILED QUESTIONNAIRE METHOD: In this method the set of questions along with a space provided for answers is sent by mail. Where the respondents are expected to answer & return to the investigator.

ADVANTAGES:

Ø  It is useful when the respondents are educated.

Ø  The area of investigation is very huge.

Ø  It is very economical & less time consuming.

DISADVANTAGES:

Ø  It is not useful when the respondents are uneducated.

Ø  All the respondents may not return the questionnaire. That is the chance of non-response is very high.

4) INFORMATION THROUGH CORRESPONDENTS OR LOCAL AGENTS: In this method local agents or correspondents are appointed in different parts of the area, & these agents send required information in regular intervals of time.

ADVANTAGES: It is mainly used whenever the information is required in regular intervals of time from the wide area.

DISADVANTAGES: The information lacks originality. The bias of correspondents effects the information.

5) SCHEDULES SENT THROUGH ENUMERATORS: In this method a schedule consisting of set of questions are sent through enumerators & these enumerators approach respondents and fills the schedule based on the information provided by the respondents.

ADVANTAGES:

Ø  It is useful in the fields whenever the respondents are uneducated.

Ø  The chance of non-response is very less.

DISADVANTAGES:

Ø  The personal views of the enumerator plays an important role.

Ø  It is time consuming & costly method.

SECONDARY DATA: The data which is collected by a person or agency for some purpose and it is utilised by the investigator for his study is called as secondary data.

NOTE:

Secondary data is useful if the primary data is not available. The main difference between the primary data & secondary data is only the degree & not the data.

Ø  The data which is primary to one person becomes secondary to other person.

Ø  The important characteristics of secondary data are

Ø  Availability of necessary data.

Ø  Suitability for the required purpose.

Ø  Reliability of the source of data.

COLLECTION OF SECONDARY DATA: The source of secondary data can be broadly divided into two types.

1)       PUBLISHED SOURCE: For the use of public, the information collected is published & made it available to all the interested parties.

The main source of published data are:

Ø  Govt publications like state & central govt reports of various committees, commission, official publications etc.

Ø  International publications like United Nations, World Bank, IMF, regularly published reports on the data collected by them on various aspects.

Ø   Semi-official publications like different research organisations & local bodies etc.

Ø  Private publications such as research scholars, Universities, annual reports of various trade union, banks etc.

2)       UNPUBLISHED SOURCES: All the information need not to be in the published form. The necessary information can also be taken from unpublished sources like personal diaries, letters, biographies & auto- biography. Unpublished data may also be available with research workers, trade associations & individuals.