## Collection of statistical data

Collection of statistical data deals with the definition of data, types data and kinds of collecting data.

A sequence of observation in a sample drawn from a population is called as statistical data.

Data which is collected first, is called as raw data or regrouped data or ungrouped data .

Data which is organized into groups, that is into a frequency distribution is called as Grouped data .

Difference between collection of statistical data:

Primary data
Secondary data
Primary data are always true as it is collected by the researcher. Secondary data is lacking originality. The investigator makes use of the data collected by other agencies.
Suitability of the primary data will be always positive because it is being collected systematically. Secondary data may or may not fit the objects of enquiry.
Primary data are costly and it will take more time consumption. Secondary data are more cheaper.

Data is one of the most important and vital aspect of any research studies. The data may be collected for a whole population or for a small group called sample. There are two types in collection of statistical data.

1. Primary data:Primary data: Data obtained from first hand information is called primary data. If a company wants to know the opinion of the people about the product that is being sold by it, it forms a team of staff members to collect opinion directly from the people. The data which will be collected directly from the people by the team of staff members is called primary data. In other words, if a data is collected Examples: Autobiography, Field research, survey reports so on.For example population census is a primary data.

Methods of collecting primary data:

We can collect the primary data through

1. Through Personal investigation
2. Through investigation by trained investigators.
3. Collection of data through questionnaire.
4. Through telephone survey.

2. Secondary data: Secondary data is the data collected by another source. The secondary data is not pure as it might have undergone some statistical treatment. Secondary data tends to be readily available.

Methods of collecting secondary data:

1. Officially like through Finance ministry, The Federal Bureaus of investigation and so on.
2. Semi official through Banks, railway boards and so on.
3. Publication of chamber of commerce, Trade Association and so on.
4. Trade journals and newspapers.
5. Researches conducted through universities and other institutions.