CHAPTER 2 COLLECTION OF DATA INTRODUCTION Data collection

CHAPTER ---2 COLLECTION OF DATA

INTRODUCTION Data collection, is in fact, the most important aspect of a statistical survey. Qualitative aspects like intelligence, honesty, good, or bad has no significance in statistics until and unless these are assigned some figures. Qualitative aspects when expressed numerically can be studied in statistics.

METHODS OF COLLECTING DATA ----PRIMARY DATA ----SECONDARY DATA

PRIMARY DATA Data collected by the investigator for his own purpose, for the first time, from beginning to end, is called primary data. It is collected from the source of origin. In the Words of WESSEL “Data originally collected in the process of investigation are known as primary data. ” Primary data are original.

SECONDARY DATA “Secondary data are those which are already in existence, and which have been collected, for some other purpose than the answering of the question in hand. ” According to Wessel, ” Data collected by other persons are called secondary data. ” These data are therefore, called second – hand data.

DISTINCTION BETWEEN PRIMARY AND SECONDARY DATA v Difference in originality v Difference in the Suitability of Objectives v Difference in Cost of Collection

METHODS OF COLLECTING PRIMARY DATA Ø Ø Ø DIRECT PERSONAL INVESTIGATION INDIRECT ORAL INVESTIGATION INFORMATION FROM CORRESPONDENTS MAILED QUESTIONNAIRE METHODS SCHEDULES SENT THROUGH ENUMERATORS

DIRECT PERSONAL INVESTIGATION In this method, data are collected personally by the investigator. There is a face-toface contact with the persons from whom the information is to be obtained.

MERITS / DEMERITS. 1. 2. 3. 4. 5. 6. Originality Accuracy Reliable Other information Uniformity Flexible DEMERITS 1. 2. 3. 4. Not Proper for Wide Areas Personal Bias Costly Wrong Conclusion

INDIRECT ORAL INVESTIGATION In the method , the investigator obtains the information not from those persons for whom the information is needed. Information is collected orally from other persons who are expected to possess the necessary information.

MERITS / DEMERITS. 1. Wider Area 2. Less Costly Expert opinion 4. Free from Bias 5. Simple 3. DEMERITS 1. Less Accurate 2. Biased 3. Wrong Conclusion

INFORMATION FROM CORRESPONDENTS In this method, the investigator appoints local agents or correspondents in different places to collect information. These correspondents collect the information in their own way and send the same to the central office where the data are processed

MERITS / DEMERITS. 1. 2. 3. 4. Economic Wide Coverage Continuity Suitable for Special Purpose DEMERITS 1. 2. 3. 4. 5. Less Originality Lack of Uniformity Personal bias Less accurate Delay in Collection

MAILED QUESTIONNAIRE METHODS In this method, a list of questions ( known as questionnaire) relating to the survey is prepared and sent to the informants by post. The questionnaire contains and provides space for answers.

MERITS / DEMERITS. 1. Economical 2. Originality 3. Wider area DEMERITS 1. 2. 3. 4. 5. Lack of Interest Lack of Flexibility Limited Use Biased Less Accuracy

SCHEDULES SENT THROUGH ENUMERATORS In this method, a questionnaire is prepared as per the purpose of enquiry. The enumerator himself approaches the informant with the questionnaire. The questionnaires which are filled by the enumerators themselves by putting questions are called schedules.

MERITS / DEMERITS. 1. Wide Coverage 2. Accuracy 3. Personal Contact 4. Impartiality 5. Complete DEMERITS 1. Expensive 2. Difficulties regarding Enumerators 3. Time Consuming 4. Not Suitable for Private Investigation 5. Inaccurate Data

ESSENTIALS/QUALITIES OF A GOOD QUESTIONNAIRE v v v v v Limited number of Questions Simplicity Proper Order of the Questions No Undesirable Questions Less Chances of Partially Calculation Pre-testing Instructions Cross Verification Request for Return

METHODS/SOURCES OF SECONDING DATA (I) PUBLISHED SOURCES (II) UNPUBLISHED SOURCES

PUBLISHED SOURCES Some of the published sources of secondary data are: 1. Government Publications 2. Semi-Government Publications 3. Reports of Committees and Commissions 4. Publications of Trade Association 5. Publications of Research Institutions 6. Journals and Papers 7. Publications of Research Scholars 8. International Publications

UNPUBLISHED SOURCES There are some unpublished sources as well. These data are collected by the government organisations and others, generally for their self use or office record. These data are not published.

PRECAUTIONS IN THE USE OF SECONDARY DATA 1. Ability of the Collecting Organisation 2. Objective and Scope 3. Method of Collection 4. Time and Conditions of Collection 5. Definition of the Unit 6. Accuracy