Data

 

DATA

 It is collection of facts, information, figures to be used for a specific purposes such as survey or analysis.

 

Types of data

1.      Qualitative data :

It represents some characteristics or attributes. It may be observed but cannot be calculated.

Example: Intelligence, Honesty, etc.

 

2.      Quantitative data :

This can be represented numerically and calculations can be done. It can be measured but cannot be observed.

Example: Height, Weight, etc.

 

 

Collection of data

Data are in fact the fundamentals of statistics. Therefore, an important step in statistical work is collection of facts and figures (data). A careful study of the technique of collection of data and their presentation in proper form is absolutely necessary as these things for the very foundation of statistical information that has to be provided. Every aspects of the problem has to be carefully examined so that the real purpose of the collection of facts may be fulfilled. As such in all statistical investigations before the collection of the data begins a large number of preliminaries have to be undergone.

Problem should be numerical: A statistical study is always undertaken to supply answers to some questions which emerge from any important problem. But all types of questions cannot be answered statistically. Therefore, the first thing to be observed by a statistical investigator is whether the problem and more particularly the question arising out of it is capable of quantitative expression.

Before the collection of data actually begins the following steps must be carefully discussed and analyzed:

1.      Object and scope of the enquiry:

The determination of the object of enquiry is a very important step in statistical investigation. If the object of the enquiry is properly determined and defined many difficulties in the collection and analysis of data are automatically removed. It becomes easy to decide which data are useful and essential for the purpose of the investigation and which are comparatively less important and can be left out. This considerably improves the degree of accuracy of the collected data. It is also essential that the scope of the enquiry is also determined beforehand. The extent to which statistical data can be useful and should be collected for the purpose of a particular investigation should be decided before the actual work of collection begins.

 

 

 

 

 

 

2.      Sources of information:

Having determined the object and scope of the enquiry it becomes necessary to think about the sources from which data have to be collected. Broadly speaking, the source of information may be either: (i) Primary or (ii) Secondary.

 

3.      Statistical units and their definition:

Need of definition. The collection of statistics necessitates measurement or counting, and as such it is essential that the unit in which the data are to be collected should be properly defined.

Physical and arbitrary units. "The unit of measurement applied to the data in any particular problem is the statistical unit." In many studies the unit to be used is conventionally fixed and is well determined and defined. Physical units of measurement like ton, pound, yard, feet; inch, hour and year, etc., are examples of this type. These units do not need any explanation or definition.

 

4.      Degree of accuracy desired:

Absolute accuracy is impossible. Before commencing the work of actual collection of data it is necessary that the investigator has some idea in his mind about the degree of accuracy which he desires in his estimates. The type of enquiry and the mode of collection of data are affected to a considerable extent by the degree of accuracy which is aimed at. It should be kept in mind that absolute accuracy is impossible to be achieved, and as such efforts must be made to achieve only a reasonable standard of accuracy. A decision about the degree of accuracy should be made with regard to the purpose of investigation and the nature of enquiry.