When investigator uses the data which is used by someone else, it is called secondary data. Sources of secondary data are as follows:
Published Printed Sources: There are a variety of published printed sources. Their credibility depends on many factors. For example, on the writer, publishing company and time and date when published. New sources are preferred and old sources should be avoided as new technology and researches bring new facts into light.
Books: Books are available today on any topic that you want to research. The use of books start before even you have selected the topic. After selection of topics books provide insight on how much work has already been done on the same topic and you can prepare your literature review. Books are secondary source but most authentic one in secondary sources.
- Journals/ periodicals: Journals and periodicals are becoming more important as far as data collection is concerned. The reason is that journals provide up-to-date information which at times books cannot and secondly, journals can give information on the very specific topic on which you are researching rather talking about more general topics.
- Magazines/ Newspapers: Magazines are also effective but not very reliable. Newspaper on the other hand are more reliable and in some cases the information can only be obtained from newspapers as in the case of some political studies.
Published Electronic Sources: As internet is becoming more advance, fast and reachable to the masses; it has been seen that much information that is not available in printed form is available on internet. In the past the credibility of internet was questionable but today it is not. The reason is that in the past journals and books were seldom published on internet but today almost every journal and book is available online. Some are free and for others you have to pay the price.
E-journals: E-journals are more commonly available than printed journals. Latest journals are difficult to retrieve without subscription but if your university has an e-library you can view any journal, print it and those that are not available you can make an order for them.
General Websites: Generally websites do not contain very reliable information so their content should be checked for the reliability before quoting from them.
Weblogs: Weblogs are also becoming common. They are actually diaries written by different people. These diaries are as reliable to use as personal written diaries.
Unpublished Personal Records: Some unpublished data may also be useful in some cases.
Diaries: Diaries are personal records and are rarely available but if you are conducting a descriptive research then they might be very useful. The Anne Franks diary is the most famous example of this. That diary contained the most accurate records of Nazi wars.
Letters: Letters like diaries are also a rich source but should be checked for their reliability before using them.
Government Records: There are two major government agencies which provide data. These are CSO and NSSO.
Central Statistical Office (CSO) It is responsible for coordination of statistical activities in the country and for evolving and maintaining statistical standards. Its activities include compilation of National Accounts; conduct of Annual Survey of Industries and Economic Censuses, compilation of Index of Industrial Production, as well as Consumer Price Indices. It also deals with various social statistics, training, international cooperation, Industrial Classification etc. The CSO is headed by a Director-General who is assisted by 5 Additional Director-Generals looking after the National Accounts Division, Social Statistics Division, Economic Statistics Division, Training Division and the Coordination and Publication Division. CSO is located in the Sardar Patel Bhawan, Parliament Street, New Delhi. The Industrial Statistics Wing of CSO is located in Kolkata. The Computer Centre also under the CSO is located in RK Puram, New Delhi.
National Sample Survey Office (NSSO)It has four divisions:
- Survey Design and Research Division
- (SDRD)–Kolkata
- Field Operations Division (FOD)-New Delhi
- Data Processing Division (DPD)–Kolkata
- Co-ordination and Publication Division (CPD)-New Delhi
- The surveys on Consumer Expenditure, Employment-Unemployment, Social Consumption (Health, Education etc.), Manufacturing Enterprises, Service Sector Enterprises are carried out once in 5years. And survey of Land and Livestock Holding and Debt and Investment are carried out once in 10 years.