Collection Of Data PDF

UNIT 1 COLLECTION OF DATA Collection of Data Objectives After studying this unit, you should be able to : Appreciate the need and significance of data collection Distinguish between primary and secondary data Know d...

UNIT 1 COLLECTION OF DATA Collection of Data Objectives After studying this unit, you should be able to : Appreciate the need and significance of data collection Distinguish between primary and secondary data Know different methods of collecting primary data Design a suitable questionnaire Edit the primary data and know the sources of secondary data and its use Understand the concept of census vs. sample Structure 1.1 Introduction 1.2 Primary and Secondary Data 1.3 Methods of Collecting Primary Data 1.4 Designing a Questionnaire 1.5 Pre-testing the Questionnaire 1.6 Editing Primary Data 1.7 Sources of Secondary Data 1.8 Precautions in the Use of Secondary Data 1.9 Census and Sample 1.10 Summary 1.11 Key Words 1.12 Self-assessment Exercises 1.13 Further Readings 1.1 INTRODUCTION To make a decision in any business situation you need data. Facts expressed in quantitative form can be termed as data. Success of any statistical investigation depends on the availability of accurate and reliable data. These depend on the appropriateness of the method chosen for data collection. Therefore, data collection is a very basic activity in decision-making. In this unit, we shall be studying the different methods that are used for collecting data. Data may be classified either as primary or secondary. 1.2 PRIMARY AND SECONDARY DATA Data used in statistical study is termed either “Primary” or “secondary” depending upon whether it was collected specifically for the study in question or for some other purpose. When the data used in a statistical study 7 Data Collection was collected under the control and supervision of the investigation, such and Analysis type of data is referred to as “Primary data”. When the data was not collected by the investigator, but is derived from other sources then such data is referred to as “secondary data”. The difference between primary and secondary data is only in terms of degree. For example, data which is primary in the hands of one become secondary in the hands of another. Suppose in investigator wants to study the working conditions of labour in a big industrial concerned. If he collects the data himself or through his agent, then this data is referred to as primary data. But if this data is used by someone else, then this data becomes secondary data. 1.3 METHOD OF COLLECTING PRIMARY DATA Primary data may either be collected through the observation method or through the questionnaire method. In the observation, the investigator asks no questions, but he simply observes the phenomenon under consideration, and records the necessary data. Sometimes individuals make the observation; on other occasion, mechanical and electronic devices do the job. In the observation method, it may be difficult to produce accurate data. Physical difficulties on the part of the observer may result in errors. Because of these limitations in the observation method, the questionnaire method is most widely used for collecting data. In the questionnaire method, the investigator draws up a questionnaire containing all the relevant questions which he wants to ask from his respondents, and accordingly records the responses. Questionnaire method may be conducted through personal interview, or by mail or telephone. Personal Interviews In this method the interviewer sits face-to-face with the respondent and records his responses. In this method, the information is likely to be more accurate and reliable because the interviewer can clear up doubts and cross-checks the respondents. This method is time-cons8uming and can be very costly if the number of respondents is large and widely distributed. Mail Questionnaire In this method a list of questions (questionnaire) is prepare and mailed to the respondents. The respondents are expected to fill in the questionnaire and send it back to the investigator. Sometimes, mail questionnaire are placed in respondents’ hands through other means such as attaching them to consumers’ products or putting them in newspapers or magazines. This method can be easily adopted where the field of investigation is very vast and the respondents are spread over a wise geographical area. But this method can be adopted only where the respondents are literate and can understand written question and answer them. 8 Telephone In this method the investigator asks the relevant questions from Collection of Data the respondents over the telephone. This method is less expensive but it has limited application since only those respondents can be interviewed who have telephones; moreover, very few questions can be asked on telephone. The questionnaire method is a very efficient and fast method of collecting data. But it has a very serious limitation as it may be extremely difficult to collect data on certain sensitive aspects such as income, age or personal life details, which the respondent may not be willing to share with the investigator. This is so with other methods also different people may interpret the questions differently and consequently there may be errors and inaccuracies in data collection. Activity A Explain clearly the observation and questionnaire methods of collecting primary data. Highlight their merits and limitation. ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… Activity B Describe the personal interviews and mail questionnaire method of data collection. ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… Activity C Point out the advantage of telephonic method of data collection. Does it have any limitations? ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… Once the investigator has decided to use the questionnaire method the next step is to draw up a design of the survey. 9 Data Collection A survey design involves the following steps : and Analysis a) Designing a questionnaire b) Pre-testing a questionnaire c) Editing the primary data. 1.4 DESIGNING OF QUESTIONNAIRE The success of collecting data through a questionnaire depends mainly on how skillfully and imaginatively the questionnaire has been designed. A badly designed questionnaire will never be able to gather the relevant data. In designing the questionnaire, some of the important points to be kept in mind are: Covering letter : Every questionnaire should be contain a covering letter. The covering letter should highlight the purpose of study and assure the respondent the all responses will be kept confidential. It is desirable that some inducement or motivation is provided to the respondent for better response. The objectives of the study and questionnaire design should be such that the respondent derives a sense of satisfaction through his involvement. Number of questions should be kept to the minimum: The fewer the question, the greater the chances of getting a better responses and having all the questions answered. Otherwise the respondent may feel disinterested and provide inaccurate answers particularly towards the end of the questionnaire. Informing the question, the investigator has to take into consideration several factors such as the purpose of study, the time and resources available. As a rough indication, the number of questions should be between 15 to 40. In case the number of questions is more than 25, it is desirable that the questionnaire be divided into various part to ensure clarity. Questions should be simple, short and unambiguous: The questions should be simple, short, easy to understand and such that their answers are unambiguous. For example, if the question is ‘Are you literate? The respondent may have doubts about the meaning of literacy. To some literacy may mean a university degree whereas to others even the capacity to read and write may mean literacy. Hence it is desirable to specify whether you have passed (a) high school (b) graduation (c) post graduation etc. Questions can be of Yes/No type, or of multiple choice depending on the requirement o the investigator. Open-ended questions should generally be avoided. Questions of sensitive or personal nature should be avoided: The questions should not be such as would require the respondent to disclose any private, personal or confidential information. For example, questions relating to sales, profits, material happiness etc. should be avoided as far as possible. If such questions are necessary in the survey, an assurance should be given to the respondent that the information provided shall be kept strictly confidential and shall not be used at any cost to their disadvantage. Answers to questions should not require calculations: The questions should be framed in such a way that their answers do not require any calculations. 10 Logical arrangement The questions should be logically arranged so that Collection of Data there is a continuity of responses and the respondent does not feel the need to refer back to the previous questions. It is desirable that the questionnaire should begin with some introductory questions followed by vital questions crucial to he survey and ending with some light questions so that the overall impression of the respondent is a happy one. Cross-check and Footnotes: The questionnaire should contain some such questions which act as a cross-check to the reliability of the information provided. For example, when a question relating to income is asked, it is desirable to include a question : “are you an income tax assessee?” For the purpose of clarity, certain questions which might create a doubt in the mind of respondents, it is desirable to give footnotes. The purpose of footnotes is to clarify all possible doubts which may emerge from the questions and cannot be removed while answer them. For example, if a question relates to income limit like 1000-2000, 2000—3000; etc., a person getting exactly Rs. 2,000 should know in which income class he has to place himself. One specimen format for a questionnaire used by IGNOU to elicit background of the participants and their expectations from the Diploma in Management course is shown below : INDIRA GANDHI NATIONAL OPEN UNIVERSITY SCHOOL OF MANAGEMENT STUDIES DIPLOMA IN MANAGEMENT OBJECTIVE – EXPECTATION ASSESSMENT FORMAT A Name: ……………………………………………………………………. B Roll Number: …………………………………………………………….. C Name of your organization: ……………………………………………… D Nature of ownership of your Organisation (tick one) [ ] Partnership [ ] Private Limited Co. [ ] Public Ltd. Co. [ ] Public Sector (Central/State) [ ] Central Government [ ] Cooperative [ ] Autonomous [ ] Any other, Specify ………………. E Designation ………………………………………………………………. F What is your job level in the organizational hierarchy of your company? Tick the appropriate box taking to Level as reference. TOP LEVEL 1 2 3 4 5 6 7 8 9 10 [] [] [] [] [] [] [] [] [] [] If none specify _____________________________________________ G What is the nature of activities of your organization? 11 Data Collection [] Manufacturing [] Professional & other services and Analysis e.g. (hospital, P&T, Education etc.) [] Trading [] Civil Administration [ ] Banking & Other [] Defence Services Financial Services [] Manufacturing [] Any other, specify H What is the scale of operation of your organization? I. Value Turnover (in Rupees) II. Number of Employees [ ] Less than 50 [ ] Less than 10 [ ] More than 50 lakhs upto 1 crore [ ] More than 10 upto 25 [ ] More than 1 crore upto 3 crore [ ] More than 25 upto 100 [ ] More than 3 crore upto 7.5 crore [ ] More than 100 upto 500 [ ] More than 12.5 crore upto 30 crore [ ] More than 500 upto 2000 [ ] More 30 crore (upto 50 crore) [ ] More than 2000 upto 10000 [ ] More than 50 crore [ ] More than 10000 I With what objectives have you joined this course? State them in order of importance ……………………………………………………………………………. Most Important 1 …………………………………………………….. 2 …………………………………………………….. 3 …………………………………………………….. 4 …………………………………………………….. 5 …………………………………………………….. 2 Would you employer appreciate and recognize your efforts in Doing this course? ( ) Yes ( ) No If Yes, is he likely to reward you? ( ) Yes ( ) No If Yes, state how …………………………………………………………. 3 How much time over and above the contact sessions, would you devote to studies for this programme every week? [ ] Less than 2 hours [ ] More than 2 hours upto 5 hours [ ] More than 5 hours upto 10 hours [ ] More than 10 hours 4 Have you had a chance to read the 3 blocks of print material sent to you this month? Yes/No If Yes, what do you like about them? 1) ……………………………….............................................................. 12  2) ……………………………….............................................................. Collection of Data 3) ……………………………….............................................................. And, what do you dislike about them? 1) ……………………………….............................................................. 2) ……………………………….............................................................. 3) ………………………………............................................................ 5 Which day(s) of the week is your office closed for weekly holiday(s) ………………………………………………….. 6 Give three preferences out of the following day and time slots for attending contact sessions. (1 = most preferred) [ ] Monday 6.30 p.m. – 9.30 p.m. [ ] Saturday 10 a.m. – 1 p.m. [ ] Tuesday 6.30 p.m. – 9.30 p.m. [ ] Saturday 6.30 p.m. 9.30 p.m. [ ] Wednesday 6.30 p.m. – 9.30 p.m. [ ] Sunday 10 a.m. – 1. p.m [ ] Thursday 6.30 p.m. – 9.30 p.m. [ ] Sunday 6.30 p.m. -9.30 p.m. [ ] Friday 6.30 p.m. – 9.30 p.m. Activity D You have been directed by your employer to carry out a market survey to ascertain the probable demand for the new drug your company is going to introduce. Prepare a suitable questionnaire in this connection. State also the type of respondents you expect to cover. ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… 1.5 PRE-TESTING THE QUESTIONNAIRE Once the questionnaire has been designed, it is important to pre-test it. The pre-testing of a questionnaire is also known as pilot survey because it precedes the main survey work. Pre-testing allows rectification of problems, inconsistencies, repetitions etc. If changes are required, the necessary modifications can be made before administering the questionnaire, some questions are found irrelevant, they can be deleted and if some questions have to be included, the same can be done. Pre-testing must be done with utmost care, otherwise unnecessary and unwanted changes may be introduced. If time and resources permit, a second pre-testing can be also be done to ensure greater reliability of results. Proper testing, revising and re- testing would yield high dividends. 13 Data Collection and Analysis 1.6 EDITING PRIMARY DATA Once the questionnaires have been filled and the date collected, it is necessary to edit this data. Editing of data should be done to ensure completeness, consistency, accuracy and homogeneity. Completeness. Each questionnaire should be complete in all respects, i.e. the respondent should have answered each and every question. If some important questions have been left unanswered, attempts should be made to contact the respondent and get the response. If despite al efforts, answered to vital questions are not given, such questionnaires should be dropped from final analysis. Consistency. Questionnaire should also be checked to see that there are no contradictory answers. Contradictory responses my arise due to wrong answers filled up by te respondents or because of carelessness on the part of the investigator in recording the data. For example, the answers in a questionnaire to two successive question “Are you married?” and “Number of children you have?” may be given by a respondent as ‘No’ and ‘Two’ respectively. Obviously, there is some inconsistency in the answers to these two questions which should be sorted out with the respondent. Accuracy. The questionnaire should also be checked for the accuracy of information provided by the respondent. It may be pointed out that this is the most difficult job of the investigator and at the same time the most important one. If inaccuracies are permitted, this would lead to misleading results. Inaccuracies may be checked by random cross-chekcing. Homogeneity. It is equally important to check whether the questions have been understood in the same sense by all the respondents. For instance, if there is a question on income, it should be very clearly stated whether it refers to weekly, monthly, or yearly income. If it is left ambiguous then respondents may give different responses and there will be no basis for comparison because we may take some figures which are valid for monthly income and some for annual income. 1.7 SOURCES OF SECONDARY DATA The sources of secondary data may be divided into two broad categories, published and unpublished. Published Sources. There are a number of national and international organizations which collect statistical data and publish their findings in statistical reports periodically. Some of the national organizations which collect, compile and publish statistical data are : Central Statistical Organization (CSO); National Sample Survey Organization (NSSO); Office of the Registrar General and Census Commissioner of India; Labour Bureau; Federation of Indian Chambers of Commerce and Industry; Indian Council of Agricultural Research (ICAR); The Economic Times; The Financial Express etc. Some of the international agencies which provide valuable statistical data on a variety of social-economic and political events are : United Nations 14 Organization (UNO); World Health Organization (WHO); International Collection of Data Labour Organization (ILO); International Monetary Fund (IMF); World Bank etc. Unpublished Sources. All statistical data need no the published. A major sources of statistical data produced by government, semi-government , private and public organizations is based on the date drawn from internal records. This data based on internal records provides authentic statistical data and is much cheaper as compared to primary data. Some example of the internal records include employees’ payroll, the amount of raw materials, cash receipts and cash book etc. It may be pointed out that it is very difficult to have access to unpublished information. 1.8 PRECAUTIONS IN THE USE OF SECONDARY DATA A careful scrutiny must be made before using published data. The user should be extra cautious in using secondary data and he should not accept it at its face value. The reason may be that such data is full of errors because of bias, inadequate sample size, errors of definitions and computational errors etc. Therefore, before using such data, the following aspects should be considered. Suitability. The investigator mush ensure that the data available is suitable for the purpose of the inquiry on hand. The suitability of data may be judged by comparing the nature and scope of investigation. Reliability. It is of utmost importance to determine how reliable is the data from secondary source and how confidently we can use it. In assessing the reliability, it is important to know whether the collecting agency is unbiased, whether it has a representative sample the data whether has been properly analyzed, as so on. Adequacy. Data from secondary sources may be available but its scope may be limited and therefore this may not serve the purpose of investigation. The data may cover only a part of the requirement of the investigator or may pertain to a different time period. Only if the investigator is fully satisfied on all the above mentioned points, he should proceed with this data a the starting point for further analysis. 1.9 CENSUS AND SAMPLE When secondary data is not available for the problem under study, a decision may be taken to collect primary data through original investigation. This original investigation may be obtained either by census (or complete enumeration) method or sampling method. When the investigator collects data about each and every item in the population, it is known as the census method or complete enumeration survey. But when the investigator studies only a representative part of the total population and makes inferences about the population on the basis of that study, it is known as the sampling method. 15 Data Collection In both the situations, the investigator is interested in studying some and Analysis characteristics of the population. The advantage of the census method is that information about every item in the population can be obtained. Also the information collected is more accurate. The main limitations of the census method are that it requires a great deal of money and time. Moreover in certain practical situations of quality control, such as finding the tensile strength of a steel specimen by stretching it till it breaks is not even physically possible to check each and every item because quality testing result in the destruction of the item itself. In most cases, it is not necessary to study every unit of the population to draw some inference about. If a sample is representative of the population then our study of the sample will yield correct inference about the total population. It should be noted that out of the census and sampling methods, the sampling method is much more widely used in practice. There are several methods of sampling which would be discussed in detail in nit 13 on ‘sampling methods’. 1.10 SUMMARY Statistical data is a set of facts expressed in quantitative form. The use of facts expressed as measurable quantities can help a decision maker to arrive at better decisions. Data can be obtained through primary sources or secondary source. When the data is collected by the investigator himself, it is called primary data. When the data has been collected by others it is known as secondary data. The most important method for primary data collection is through questionnaire. A questionnaire refers to a device used to secure answers to questions from the respondents. Another important distinction in considering data is whether the values represent the complete enumeration of some whole, known as population or universe, or only a part of the population, which is called a sample. 1.11 KEY WORDS Census is the collection of each and every item in the given population or universe. Population is the collection of items on which information is required Primary Data is the collection of data by the investigator himself. Questionnaire is a device for getting answers to questions by using a form to which the respondent responds. Sample is any group of measurements selected form a population. Secondary Data is the collection of data compiled by someone other than the user. 16 1.12 SELF-ASSESSMENT EXERCISES Collection of Data 1. Distinguish between primary and secondary data. Discuss the various methods of collecting primary data. Indicate the situation in which each of these methods should be used. 2. Discuss the validity of the statement : “A secondary source is not as reliable as a primary source”. 3. Discuss the various sources of secondary data. Point out the precautions to be taken while using such data. 4. Describe briefly the questionnaire method of collecting primary data. State the essentials of a good questionnaire. 5. Explain what precautions must be taken while drafting a useful questionnaire. 6. As the personnel manager in a particular industry, you are asked to deter4mine the effect of increased wages on output. Draft a suitable questionnaire for this purpose. 7. If you were to conduct a survey regarding smoking habits among students of IGNOU, what method of data collection would you adopt? Give reasons for your choice. 8. Distinguish between the census and sampling methods of data collections and compare their merits and demerits. Why is the sampling method unavoidable in certain situation? 9. Explain the terms ‘Population’ and ‘sample’. Explain why it is sometimes necessary and often desirable to collect information about the population by conducting a sample survey instead of complete enumeration. 1.13 FURTHER READINGS Clark, T.C. and E.W. Jordan. Introduction to Business and Economic Statistics, South-Western Publising Co.: Ohio. Enns, P.G. Business Statistics, Richard D. Irwin Inc.: Homewood. Gupta, S.P. and M.P. Gupta. Business Statistics, Sultan Chand & Sons: New Delhi Levin, R.I. Statistics for Management, Prentice Hall of India: New Delhi. Moskowitz, H. and G.P. Wright. Statistics for Management and Economics, Charles E. Merill Publishing Company : Ohio 17