Data means information. Everyone collects interprets and uses the information. Information may be through conversations, newspapers, televisions and radios. Data collection refers to gathering the information required for the study. The source may be primary or secondary and are expressed in a numeric form that helps in a calculation and simplifying the problems.
Pre-requisites of Data Collection
The following steps are to be considered for the collection of required information:
Objective of The Study Without pointing out the objective of the study, the data collection can mislead the analysis. It just wastes the resources of an investigator. Hence, the objective of the study must be pre- specified.
Scope of Inquiry Scope of the inquiry relates to the coverage of the study. So it must be clear before the data is to be collected. For example, if an investor wants to calculate price index numbers, it must specify whether to investigate a particular area or only certain area.
Units to be Used The units of measurement and analysis must be clear. The main requisites about the statistical units to be used are; it should be specific, stable, uniform, rigidly defined, and appropriate to the inquiry.
Sources of Data and Information Data and information must be collected first before investigation for the appropriate data.Proper organization of the data is very essential for conducting the activities smoothly and efficiently.
Method of Data Collection Two methods can be used for collecting the data and they are census method and sample method. Census method gives more accurate result than sample method but is more costly and time-consuming comparing to sample method.
Degree of Accuracy At the beginning of the data collection degree of accuracy must be determined.There must be correct accurate and reliable data since data is the building block for carrying on certain activities.
Types of inquiry Statistical inquiry may be of different types such as official, semi-official, unofficial, confidential, non-confidential, regular or ad-hoc. Such type of inquiries should be made clear before data collection.
The collection of data is a primary need for statistical information. There are two types of data:
1. Primary Data
Data collected for the first time by an investor originally from its basic source for statistical inquiry are known as primary data. Primary data are the first-hand data and are original in character. They are like raw material to be used in statistical analysis. For example, Central Bureau of Statistics (CBS) of Nepal collects the data in a various field, such data are primary in nature.
Data that are collected by the investor himself for a specific inquiry or study are called primary data. It is original in character and generated by a survey conducted by a research institution or an organization. The various methods of collection of primary data are as follow:
i) Direct personal interview method:
This method is one of the best methods for collection of primary data where the investigator itself collects data through personal contact. He approaches the object, conducts the inquiry on the spot, collects information and does the needful, so as to get the complete information.
The data are more reliable and accurate.
The investigator can clarify any doubts that the informants may have during the interview.
Answer of the sensitive questions can be gathered by this method.
Supplementary information on informant's personal aspects can be noted which may help later to interpret some of the results.
It is very costly and time-consuming.
It is very difficult when the number of persons to be interviewed are in large and the persons are spread over a wide area.
Under this method, personal prejudice and bias are greater.
If informants hesitate to give information, proper information cannot be obtained.
ii) Indirect Oral Interviews method:
Under this method, the investigator contacts witnesses or neighbors of friends or some other third parties who are capable of supplying the necessary information. In the case of sensitive question such as wealth accumulation, prostitution, illegal activities, this method of indirect oral interviews is applied. For example, if a person is killed at a certain place, the persons living in neighborhood and witnesses are likely to give information on the cause of murder. But the investigator himself is not in touch with informants.
It is cheaper and required less time and manpower.
A wide area can be covered easily.
Views and suggestions of the specialists on the given problems can be considered.
Sensitive and personal information can be collected from the person who is closer to the informant.
There may be personal biases.
If the witness is not serious, correct information cannot be extracted.
iii) Information from Mailed Questionnaire:
In this method, a list of questions relating field of inquiry is prepared and is sent to all the informants by post. The list of questions is technically called questionnaire. A covering letter accompanying the questionnaire explains the purpose of the investigation and the importance of correct information and requests the informants to fill the blank spaces provided and to return the form within specified time.
It is relatively cheap.
This method is used for extensive inquiries covering a wide area.
The personal bias of enumerators is completely avoided.
This method cannot be used if the informants are not able to understand and reply the questions.
Most of the informants may not respond.
It is difficult to verify the correctness of the information furnished by respondents.
iv) Information from Local Agents and Correspondence:
Under this method, the investigator appoints different local agents or correspondents in different places and complies the information sent by them. This method is cheap and appropriate for extensive investigations. This method is adopted in those cases where information is to be collected periodically from a wide area for a long time.\
It is very cheap and economical method.
This method covers very wide range of geography.
If investigators need information in regular interval of time, this method is most appropriate.
The result is bound to be biased due to prejudiced.
The data obtained will not be reliable.
This method is hard to apply in remote areas due to weak communication.
v) Questionnaires to be Filled by Enumerators:
Under this method, the interviewers take the schedules, meet the informants and fill up their replies. A schedule is filled by the interviewers in a face to face situation with the informants. This method is suitable for extensive surveys.
It is useful in extensive enquiries.
It can be adopted even if the informants are illiterate.
If the interviewers are trained, the information collected is reliable.
Supplementary information can be collected.
This method is costly.
This method may not ensure accuracy ,enumerators are likely to be biased.
This method is more time consuming.
2. Secondary Data
Data already collected and used by other and is still useful for other investigator are called secondary data. These type of data is not original. They are also called second-hand data. It is like finished good and it saves time and cost. Secondary data is cheap to obtain. Secondary data are to be carefully and critically examined before they are used. Large quantities of secondary data can be obtained through the internet. The following precautions should be adopted while using secondary data:
Reliability: Secondary data might not be reliable. The reliability of data can be tested by finding out: i) How has the data been collected and processed? ii) Were the proper methods used to collect the data? iii) Where and when the data were collected?
Suitability: Before collecting the secondary data the investigator must confirm whether the data available are suitable or not. For example, if we want to find out the number of students passed in economics but we have the data of the number of the student passed in mathematics then such data will not be suitable for the purpose of investigation.
Adequacy:Reliability and suitability of data are not enough for the purpose of the inquiry. The data must cover the study area which should not be too wide or too narrow. Otherwise, the result cannot be generalized. For example, if we want to find out the percentage of women in Nepal and the available data is only of Biratnagar, then such data will be inadequate for the purpose of our inquiry.
Source of Secondary Data
There are two sources of collecting secondary data:
1. Published Sources:
The various sources of published data are:
Official publication published by the planning commission, ministry, government agencies etc.
Reports and official publications of international bodies such as international finance corporation, United Nations Organizations, etc.
Semi-official publications of various local bodies such as municipal corporation, water supply corporation, Nepal Telecommunication, Nepal Oil Corporation, Dairy Development Corporation etc.
Private publications such as reports of NGOs and INGOs, publication brought out research agencies, research scholars, financial and economic journals etc.
2. Unpublished Sources:
There are various sources of unpublished data such as records maintained by the various government and private offices, the study made by research institutions, scholars etc. Such sources can also be used where necessary.