Primary Data

The data collected for the first time by the investigator himself from the field of enquiry is called "primary data". An investigator can collect using different methods for his own purpose of investigation. Hence, the primary data is original in character.

For example, if an investigator wants to investigate the incomes of workers of all the companies of Country, then the data (i.e. income) collected by the investigator himself or his representative, are called primary data.

Method of Primary Data Collection

The following are the various methods of collecting primary data.

  1. Direct personal contact
  2. Indirect oral interviews
  3. Informations from correspondents
  4. Mailed questionnaire
  5. Questionnaire sent through enumerators

1. Direct personal contact (i. e interviews)

In this method, the investigators (or, interviewer) collect data by personally contacting the respondents. The investigators must go to the related field and have to meet and interview each and every individual to collect relevant data for his investigation.

For example, if one is interested in studying the salaries of lecturers working in the campuses, then the investigator must visit the campuses and collect necessary informations from lectures.

The method can give accurate results only if the informants (i.e. individuals who give information) and investigator are unbiased. If the field or investigation is narrow, then this method is applicable.


  1. Information collected by this method is more accurate
  2. Responsibility of the data is very high
  3. Extra supplementary information can be obtained which may help in drawing conclusion
  4. Proper language and technique can be adopted according to the nature and status of the informant
  5. Sensitive type of questions can be asked at such time only when the informants feel at home with the interviewer


  1. It consumes time and money
  2. Accurate informations can not be obtained due to personal bias
  3. This method is not applicable if the field of investigation is not narrow
  4. The data will not be reliable if the interviewer is not well- trained, qualified and intelligent

2. Indirect oral interviews

In this method, the informations are collected by the interviewer from third person who are directly or indirectly concerned with the informations to be collected. The person is said to be the "witness". This method is generally adopted, when the informants are unable to give their information directly.

For example, in the study of the drinking (or smoking) habits of the society, one who drinks (or smokes) is unable to give information of his bad habits. In this case, it is necessary to get informations from those who may know him. This method is usually followed by enquiry committee or commission appointed by the government.

In this method, the persons are selected on following basis: 

  • they should explain the full facts of the problem
  • they should be capable of giving correct answers
  • they shouldn't be personal biased.


  1. It saves money, time and labour
  2. A wide area can be taken as the field of investigation
  3. The opinion and suggestion of experts can be solicited


  1. Exact informations may not be obtained due to the doubtful information given by witnesses.
  2. The investigator can twist the facts, if he is a biased person.

3. Informations from correspondents

In this method, local agents known as "correspondents" are appointed in frent fields under study. The necessary informations are available from those pointed correspondents to the investigator. This method is more suitable if the normations are to be collected from wide area.


  1. Informations of wide area can be obtained
  2. Regular informations are available
  3. Results are obtained easily and cheaply
  4. Qualitative informations are obtained due to the appointment of local agent


If the appointed local agents are personally biased, informations obtained may not be accurate and reliable 

4. Mailed questionnaire

In this method, a list of questions (i.e. questionnaire) relating to the investigation, is prepared and sent by post to the various informants. The informants are requested to fill up the questionnaire and is sent back to the enquiry office with the time mentioned. This method is suitable for the regions where people are educated and cooperative.


  1. Real informations are obtained as the questionnaires are filled by informant.
  2. Informations are obtained quickly and cheaply
  3. If the informants are spread over a wide geographical area and the informations are to be collected from wide area, then this method is suitable.


  1. This method is suitable only for those regions where people are educated and cooperative.
  2. Most of the questionnaires are not returned back by the informants due to their non-responsibilities.
  3. The results may not be accurate due to the misunderstanding of the given set of questions

5. Questionnaire sent through enumerators

In this method, local agents (called enumerators) are appointed and trained properly. Then the questionnaires are sent to the informants through the enumerators but not by post. The enumerators visit door to door along with their questionnaires and the informations given by the informants are noted.

The data collected by the enumerators are sent back to the investigator (or the office concerned) for further processing of data. This method is usually suitable research organizations.


  1. This method is suitable even for uneducated informants
  2. The chances of responsibility is high due to the personal contact between enumerator and informant.
  3. Enumerators can ask some additional questions relating to the investigation


  1. It is very labourous, expensive and time consuming method.
  2. This method is not free from the biasness of the enumerators.
  3. If the enumerators are not well - trained, the data collected may not be correct.

Secondary Data

The data prepared by highly skilled man powers is called "Secondary data".

In other words; the data which are initially collected by someone but obtained from some published or unpublished sources are called "Secondary data". This data is not original in character.

The difference between primary and secondary data is only of one degree Data which is primary in the hand of one person becomes secondary to the hand of other. 

Method of Secondary Data Collection

In this case, the investigator uses only those data which have already been collected and used by others. Secondary data can be collected from the following two sources:

  1. Published Sources
  2. Unpublished Sources

1. Published Sources

The various sources of secondary data are

  1. Official publication published by
      • Government such as report of C.B.S (Central Bureau of Statistics), ministries of H.M.G pay commission etc.
      • Reports of International Organisation such as World Health Organisation, U.N.O.(United Nations Organisation),
      • World Bank,
      • International Labour Organisation,
      • International Monetary Fund etc.
  2. Semi-official publications, published by various local organizations like
      • Nepal Rastra Bank,
      • Industrial Service Centre,
      • Nepal Food Corporation etc
  3. Non- governmental (i.e. private) publications, such as
      • Reports of N.G. O and I. N. G. O
      • Reports of Nepal chamber of commerce.
      • Publications of individual intellectuals and scholars.
      • Financial and economic journals.
      • Reports of trade associations, magazines, market reports etc.

Note: The publications may or may not be regular with respect to time

2. Unpublished Source

All the informations may not be published but may be suitable for the purpose of investigation. In other words, an unpublished information may be useful to investigator for his conclusion.

The sources of unpublished data are

  • report of private offices
  • hospital records
  • material collected by researchers
  • records of campus administrations etc.