Secondary data are those which have already been collected by someone else and which have already been passed through the statistical process.
Usefulness of Secondary Data:
1. Cost of collecting data save so it is more economical.
2. Most of the secondary data are ‘Instant’ since they already exist and merely need to be discovered.
3. Secondary data are sometimes available even in those case where primary investigation are not possible.
4. There is no problem to design information gathering instrument as information is already collected by another means.
Advantages of Schedule Method:
1. Information can be gathered even when the respondents happen to be ill ferrate.
2. Information collected is reliable more accurate than other methods.
3. Direct personal contact is established with respondents.
4. Information is collected well in time as they are filled in the enumerators.
5. Detects in sampling are deducted.
6. Human elements make the study more reliable and dependably.
1. There are difficulties in sending enumerator over a relatively wider area.
2. Physical appearance of questionnaire is not quite attractive.
3. Data collection through schedules is relatively more expensive.
4. Need of trained field workers.
Difference between Primary and Secondary Data:
Examples of Secondary Data:
1. Office of economic adviser, Government of India, is the originating source for the data on whole sale prices. In contrast, a publication such as R.B.I. Bulletin containing some parts of thee series of wholesale prices, is a secondary source.
1. No investment to collect data so its unit cost is very low.
2. Simple and easiest procedure of research.
3. Less paper work.
1. Its utility is limited.
2. Information is old. Sometime related information is obsolete.
Evaluation of Secondary Data:
Use of secondary data is cheaper than that of primary data there are four requirement that must be met.
1. Availability of secondary data.
Detailed approach for evaluating secondary data are discussed below:
Eight steps are grouped into three categories, namely:
1. Applicability to the project objectives.
2. Cost of acquisition.
3. Accuracy of data.
Under each of these categories, answers to specific questions are sought. Thus some of the basic questions are-Do the data apply to the population of interest. Do they apply to the time period of interest can the units and classifications presented apply?
It answer to these and similar then questions are in the affirmative one may proceed with the use of secondary data. Otherwise one should drop the idea of using them. At the end the author rightly cautions the researcher to exercise great care before using the secondary data “Because of the natural tendency of many people to hide a shaky foundation beneath an elaborate superstructure”.