Secondary data are data that are taken from research works already done by somebody and used for the purpose of the research data collection. The reason why secondary data are being increasingly used in research is that published statistics are now available covering diverse fields so that an investigator finds required data readily available to him’ in many cases. For certain studies like stock price behavior, interest and exchange rate scenario, etc. only secondary data are used.
There are two broad categories of secondary data – internal secondary data and external secondary data.
- Internal secondary data: Internal (secondary) data refers to information that already exists within the company in which the research problem arises. For instance, in many companies, salesmen routinely record and report their sales. Examples of secondary data include records of sales, budgets, advertising and promotion expenditures, previous marketing research studies and similar reports. Use of such secondary data can help the marketing manager analyse the effect of the different elements of the marketing mix, develop a marketing plan, make Budget and sales territory allocations, and, in general, help in managerial decision making.
- External secondary data: External (secondary) data refers to information which is collected by a source external to the firm (whose major purpose is not the solution of the particular research problem facing the firm). There are three major categories of external data;
- Government sources and publications
- Business reference sources
- Commercial agencies
Sources of Secondary Data
Secondary data are obtained from personal documents and public documents.
1. Personal Documents
These documents are recorded by the individuals. An individual may record his views and thoughts about various problems and without knowing for these documents at a latter data so formed a subject or source of study.
Personal documents may be categorized or divided under the following heads for the convenience of the study:
- Life History: Life history, generally speaking contains all kinds of biographical , material, from the point of view of personal documents only an autobiography which contains description and views about social and personal events is a life history. It may be further classified under the following three sub-heads: Spontaneous Autobiography, Voluntary Autobiography of self record, and Compiled life history.
- Diaries: Many people keep diaries in which they record the daily events of their life and their feelings and reactions relating to those events. Some of the diaries are also published later on. Diaries are the most important source of knowing the life history of a person. If they have been written continuously over long periods.
- Letters: Letters also provide useful and reliable material on many social problems. They throw light upon more intimate aspects of an event, and clarity the stand taken by a person regarding it. They are helpful in giving an idea of the attitudes of a person and the trend of his mind. The validity of letters is beyond all doubt and they should be accepted as prima facie proof of the attitude of the writer. In such social problems as love, marriage or divorce the letters can supply much revealing information.
- Memoirs: Some people write memoirs of their travels, important events of their life and other significant phenomena that they come across. These memoirs provide useful material in the study of many a social phenomena. Memoirs are different from dairies in the sense that they describe only some events and are more elaborate than the dairy. Memoirs of travelers have provided us with useful information regarding the language, social customs, religious faiths, culture and many other social aspects of the people they visited.
2. Public Documents
Public documents are quite different from personal documents. They deal with the matters of different interest. Public documents may be divided into the following two categories:
- Unpublished Records: Unpublished records give matters of public interest not available to people in published form. Everybody cannot have access to them. Proceedings of the meetings, noting on the files and memoranda etc., form the category of unpublished records. It is said that these records are reliable. Since there is no fear of their being made public the writers give out their views clearly.
- Published Records: Published records are available to people for investigation and perusal. Survey, reports, report of survey enquiries and such other documents fall under this category.
The data contained in these documents are considered by some people as quite reliable because the collecting agency knows that it shall be difficult to test, while others are of the view that if the data are to be published the collecting or publishing agency does some window dressing, as a result of which the accuracy is sometimes postulated.
Now most of the information that is available to people and researchers in regard to social problems is to be found in form of reports. The reports published by Government are considered as more dependable. On the other hand some people think that the reports that are published by certain individuals and agencies are more dependable and reliable.
- Journals and Magazines: Journals and magazines are important public documents including a wide variety of information which .can be usefully utilized in social research. Most of these information are very much reliable. Letters to the editors published in various magazines and journals are an important source of information.
- Newspapers: Newspapers publish news, discussion on contemporary issues, reports of meetings and conferences, essays and articles on living controversies and the letters of the readers to the editors. All this is an important source of formation for different kinds of social research.
- Other Sources: Besides the above mentioned public documents, film, television, radio and public speeches etc., are other important sources of information. They supply useful information – about contemporary issues. The investigator, however, should be capable of sorting out the reliable material and distinguishing it from the unreliable material advanced by these sources.
Advantages of Secondary Sources of Data
Following merits are usually claimed for using secondary data source.
- Provides an insight into total situation: The purpose of use of available materials is to explore the nature of the data and the subjects to get an insight into the total situation. While looking for the data required by the researcher he may uncover many more available data than are often assumed to exists and hence contributes significantly to the unfolding of hidden information.
- Helps in the formulation of hypothesis: The use of documentary sources sometimes, helps in the formulation of research hypothesis. While an investigator may have one or two hypotheses which he might have deduced from theory, the study of available materials may suggest further hypotheses. If a research idea or hypotheses can be formulated in such a manner that the available recorded material bears on the question, the use of such material becomes possible.
- Helps in testing the hypotheses: The available records may also help in testing the hypothesis.
- Provides supplementary information: Available documents may be used to supplement or to check information gathered specifically for the purposes of a given investigation. For example, if one has drawn in random sample of a small group in order to interview individuals, the accuracy of one’s sample could be checked by comparing socio-economic data of the sample, like income, education standard, caste, family size etc., with the same data of the most recent census or with available data in local Government offices.
Disadvantages of Secondary Sources of Data
The following are the demerits of using secondary data sources for research purpose.
- Collected for a specific purpose: Data are often collected with a specific purpose in mind, a purpose that may produce deliberate or unintentional bias. Thus, secondary sources must be evaluated carefully. The fact that secondary data were collected originally for particular purposes may produce other problems. Category definitions, particular measures or treatment effects may not be the most appropriate for the purpose at hand.
- Old data: Secondary data are by definition, old data. Thus, the data may not be particularly timely for same purposes.
- Aggregation of data in Inappropriate Unit: Seldom are secondary data available at the individual observation level. This means that the data are aggregated in some form, and the unit of aggregation may be inappropriate for a particular purpose.
- Authenticity: The authenticity of same secondary sources of data is doubtful.
- Context change: Secondary data refer to a given situation. As situations change, the data lose their contextual validity.