As this tutorial you’ll able to know about method of collection Primary data, source of primary and secondary data, Problems involved in the collection of primary and secondary data in statistics….
The data collected by the researcher/investigator for the purpose of the investigation are called primary data. The data burrowed from the other sources are called secondary data. They are less reliable, less valid and less accurate data as compared to the primary data. They do not contain the original characteristics. The major sources of secondary data are reports and records, books, newspapers, magazines etc. Generally, secondary data are used in low-level research activities. Primary data are fresh, first-hand, reliable, valid and accurate .They contain original characteristics. Major sources are experiments, surveys and different researches .Generally, they are used in high-level research activities.
There are 5 Method of collection primary data are discuss below:
- Direct personal interview method.
- Indirect personal interview method.
- Information through correspondence method.
- Mailed questionnaire method.
- Schedule sent through enumerators method.
Direct personal interview method.
When fresh, accurate, reliable and valid data are required then direct personal interview method is preferred. In this method, the investigator meets the respondents personally and asked the necessary questions and collect the required data from them. This method is very useful for small number of respondents.
Merits and Demerits of collecting data as Direct personal interview method as follows:
- Data are accurate, reliable and valid.
- The accuracy of data can be verified in the spot.
- It is not useful method for large area of inquiry.
- It is expensive method.
Indirect personal interview method:
When the respondents hesitate to provide information directly then indirect personal interview method is preferred. This method is suitable for collecting the information regarding personal property, income, habits, family planning, prostitution etc. In this method, investigator collects the information of the respondents (second persons) with the help of third person (called ‘witness’) who is familiar with the respondents.
What are the advantage and disadvantage of collecting data by Indirect personal interview method:
- It is a convenient method of collecting sensitive information.
- It can be used for wider area of inquiry.
- Third person (witness) may be biased.
- It is likely to get inaccurate and unreliable information
Information through correspondence method
This method is specially useful for news media. In this method, the investigator appoints the correspondents in different place to collect information. The correspondents collect the necessary information and send to the central office (investigator).
Here the some Merits and Demerits of collecting data as Information through correspondence method as follows:
- This method is less expensive.
- The information from wider area can be collected.
- Correspondents may be biased.
- Information through this method may not uniform.
Mailed questionnaire method:
This method is suitable for wide area of investigation. In this method, a set of questions (questionnaire) is prepared at first and the questionnaire is sent to the respondent in their address by mail or email or by the link person. The respondents are requested to answer these questions and return back to the researcher.
some Merits and Demerits of collecting data as Mailed questionnaire method are as follows:
- This method is suitable for wide area of investigation.
- It is very economic method.
- There is high degree of non-response error.
- It is likely to provide wrong information from informants.
Schedule sent through enumerators:
When reliable, valid, and accurate data should be collected from the large area of inquiry and from all types of people (illiterate or literate) then schedule method is preferred. In this method, a set of questions (called schedule) is prepared and a training is given to the appointed enumerators. Then, the enumerators meet with the respondents and asked the questions from the schedule, and collect the required information. The enumerators fill the schedule themselves. This method has been applying in different censuses.
Merits: Schedule sent through enumerators method
- This method is suitable for wide area of inquiry.
- Non-response error will be minimized in this method.
Demerits: Schedule sent through enumerators method
- This is time consuming method.
- It is expensive method.
Problems involved in the collection of primary and secondary data
While collecting the primary and secondary data, there may arise various problems. The main problems are;
- Lack of time, money and manpower.
- Lack of transportation facilities.
- Lack of expertise and trained persons.
- Lack of reliable and valid sources of data.
- High degree of non-response error.
- Biasness of the enumerators/respondents etc.
Primary and secondary data source
The main sources of primary data are experiments, surveys and other resources. And main sources of secondary data are records, reports, books, newspaper, internets, magazines etc.
Difference between primary and secondary data: