Enumerate the various methods of collecting primary and secondary data.

1. Direct Personal Interview : According to this method, data are collected by the investigator personally from persons who are the subject to enquiry. He interviews personally every one who is in a position to supply information he requires. We can use this method of collection of data when area of enquiry is limited or when a maximum degree of accuracy is needed. One can think of personal enquiry in a case of collection of information regarding family budget and living conditions in a group area. The investigator must be skilled, tactful, accurate, pleasing and should not be biased.

2. Indirect Personal Interview : Direct personal enquiry cannot be used in the case of the refusal and reluctance of the persons who are to be interviewed. Then an indirect personal enquiry can be conducted to get a necessary information from an indirect source. Persons who have the knowledge of relevant material are interviewed and asked questions for collecting the data.

3. In this method, local residents or correspondent are appointed in the different parts of the investigation area. These agents regularly supply the information to the central office or investigator. They collect the information according to their own judgements. Radio and newspaper agencies generally obtain information about strikes, thefts, accidents etc. by this method, It is adopted by Government departments to get estimates of agricultural crops and the wholesale price index number. It is suitable when the information is to be obtained from a wide area and where a high degree of accuracy is not required.

4. Mailed questionnaires : A list of questions relating to inquiry, which is called schedule or questionnaire, is prepared. The list of questions provides a space for each answer. Schedules are sent to informants by post, with a request to answer and return it within a specified time. Such schedules generally have prepaid postage stamp affixed to them. If necessary, an assurance is given that the answers will be kept confidential.

5. Questionnaire to be filled by enumerators : Mailed questions method poses a number of difficulties in collection of data. Generally questionnaires received are incomplete, inadequate and unrepresentatives. The second alternative approach is to send trained investigators or enumerators to informants with standardized questionnaire which are to be filled in by the investigators. The investigator help the informations in recording their answers. The investigators should behonest, tactful and painstaking. This is the most common method used by research organisations.

Secondary data may be either (a) Published or (b) Unpublished.

Published Sources :

(i) Government Publications : Different ministers and departments of Central and State

Governments publish regularly current information along with statistical data on a number of subjects. This information is quite reliable for related studies. The examples of such publications are : Annual Survey of Industries, Labour Gazette, Agriculture Statistics of India.

(ii) Publication of International Organization : We can obtain valuable international statistics from official publication of different international organizations, like, The United Nations Organisation (U.N.O.) International Labour Organisation (I.L.O.) International Monetary Fund (I.M.F.) etc.

(iii) Semi-official Publications : Local bodies such as Municipal Corporations, District Boards etc. publish periodical reports which provide factual information about health, sanitation, births, deaths etc.