1. What are the sources of data?

     The data are collected through the following ways. They are:

    (i) Primary sources of data.
   (ii) Secondary sources of data.

2. What do you mean by primary source of data?

     The data which are collected for the first time by an individual or the group of individuals, institution / organizations are called primary sources of the data.

3. What you mean by secondary sources of data?

    Data collected from any published or unpublished sources are called secondary sources of data. It includes government publications, documents and reports.

4. What are the sources of primary data?

     The sources of primary data are:

    (i) Personal observations
   (ii) Interview
  (iii) Questionnaire / Schedule
  (iv) Other methods

5. What is personal observation?

     Personal observation refers to the information by an individual or group of individuals through direct observations in the field.Through a field survey information about the relief features, drainage patterns, types of soil and natural vegetation, as well as population structure,sex ratio, literacy, means of transport and communication, urban and rural settlements etc is collected.

6. What is interview method?

    In interview method, the researcher gets direct information from the respondent through dialogues and conversations.

7. What is questionnaire method?

    In questionnaire method, simple questions and their possible answers are written on a plain paper and the respondents have to tick mark possible answers from the given choices. The objectives of the survey should be clearly mentioned in the questionnaire. This method is useful in carrying out the survey of a larger area.

8. Define data?

    Data are defined as numbers that present measurements from the real world.

.9. Define information?

     Information is defined as either a meaningful answer to a query or a meaningful stimulus that can cascade into further queries.

10. What is government publications?

      The publications of the various ministries and department of the Government of India, State Government and District Bulletins are one of the most important sources of secondary information. These include the Census of India, published by the office of the Registrar General of India, reports of the National Sample Survey.

 11. What are the published sources of data?

      The secondary sources of data are:

      (i)  Government publications
     (ii)  Semi / quasi government publications
    (iii)  Industrial publications
    (iv)  Private publications
     (v)  Newspapers and magazines
    (vi)  Electronic media

12. What is semi / quasi government publications?

      The publications and reports of Urban Development Authorities and Municipal Corporations of various cities and towns, Zila Parishads (District Councils)etc fall under this category.

13. What is an international publication?

      The international publications comprise yearbooks, reports and monographs published by different agencies of the United Nations such as United Nations Educational, Scientific and Cultural Organization (UNESCO), United Nations Development Programme (UNDP),World Health Organization(WHO),Food and Agricultural Organization (FAO)etc some of the important publications of the United Nations that are periodically published are Demographic Year Book, Statistical Year Book and the Human Development Report.

14. What is private publication?

      The yearbooks, surveys, research reports and monographs published by newspapers and private organizations fall under this category.

15. What is electronic media?

      The electronic media specially internet has emerged as a major source of secondary data in recent times.

16. What are the unpublished sources of data?

      The unpublished sources of data are:

      (i)  Government documents
     (ii)  Quasi-government records
    (iii)  Private documents

17. What are government documents?

      The published reports, monographs and documents are yet another source of secondary data. These documents are prepared and maintained as unpublished record at different levels of governance.

18. What are quasi-government records?

       The periodical reports and the development plans prepared and maintained by different Municipal Corporations, Districts Councils and Civil Service Departments are included in quasi-government records.

19. What are private documents?

      Private documents include unpublished reports and records of companies, trade unions, different political and a political organizations and resident welfare associations.

20. What is raw data?

      The data collected from primary or secondary sources initially appear as a big jumble of information with the least of comprehension. This is known as raw data. To draw meaningful inferences and to male them usable the raw data requires tabulation and classification.

21. What is statistical data?

      One of the simplest devices to summarize and present the data is the statistical table. It is a systematic arrangement of data in columns and rows. The purpose of table is to simply the presentation and to facilitate comparisons. This table enables the reader to locate the desired information quickly.

22. What is percentage or ratio?

      Sometimes data are tabulated in a ratio or percentage form that are computed from a common parameter, such as literacy rate or growth rate of population,percentage of agricultural products or industrial products.

23. What is the formula of literacy rate?

      Literacy rates of India over the decades in a percentage form. Literacy rate is calculated as:

                                         Total literates   _*  100
                                       Total population

24. What is index number?

       Index number is a statistical measure designed to show changes in variable or a group of related variables with respect to time, geographical location or other characteristics. It is to be noted that index numbers not only measure changes over a period of time but also compare economic conditions of different locations, industries, cities or countries. Index number is widely used in economics and business to changes in price and quantity.

25. What is the formula of index number?

       There are various methods for the calculation of index number.However, the simple aggregate method is commonly used. It is obtained using the following formula:

                  E_{q1   * 100}
                  E_q0                              
      Eq_i=  Total of the current year production.
      Eq_o= Total of the base year production.

26. What is grouping of raw data?

       The grouping of the raw data requires determining of the number of classes in which the raw data are to be grouped and what will be the class intervals.The selection of the class interval and the number of classes however depends upon the range of raw data.

27. What is frequency distribution?

       When numbers of individuals are known as frequency and the column represents the frequency distribution. It illustrates how the different values of a variable are distributed in different classes.

28. What are the classifications of frequencies?

       Frequencies are classified into two. They are:

      (i) Simple frequencies
     (ii) Cumulative frequencies

29. What is simple frequency?

      Simple frequencies is expressed by ‘f’ and represent the number of individuals falling in each group. The sum of all the frequencies assigned to all classes represents the total number of individual observation in the given series. In statistics, it is expressed by the symbol N that is equal to Ef.

30. What is cumulative frequency?

       Cumilative frequency is expressed by ‘cf’ and can be obtained by adding successive simple frequencies in each group with the previous sum.

31. What is exclusive method?

      In exclusive method, a group is excluded of its upper limits.

32. What is inclusive method?

      In inclusive method, a value equal to the upper limit of a group is included in the same group.Therefore,it is known as inclusive method.

33. What is frequency polygon?

      A graph of frequency distribution is known as the frequency polygon.It helps in comparing the two or more than two frequency distributions.The two frequencies are shown using a bar diagram and a line graph respectively.

34. What is ogive?

      The curve obtained by plotting cumulative frequencies is called an ogive.It is constructed either by the less than method or the more than method.

35.What are cumulative frequency table?

     When the frequencies are added they are called cumulative frequencies and are listed in a table called cumulative frequency table.