Secondary data is information used in research that has already been collected for another purpose, rather than directly by the researcher. As the data is, by definition, already available there are no specific methods of secondary data collection although sources of secondary data vary and can include public records, census data, newspapers and surveys.
Data collection for research can be time-consuming and expensive so using existing, or secondary, data can be a cost-effective alternative. However, high quality research does still need a methodical approach so you should ensure the secondary data is accurate, still valid depending on how long ago it was collected, from a reliable and identified source and appropriate to your research.
Secondary data may be qualitative (descriptive) or quantitative (numerical). Qualitative data sources include newspapers, books, diaries, interview transcripts, etc., and quantitative sources typically include surveys and statistics, many of which are available from the public records office or the national archives.
Although a researcher does not actually collect secondary data, it is important to understand the collection method used in the primary instance. A systematic researcher should check the source of the original research thoroughly and be aware of any reasons that may limit its usefulness.
Problems with using secondary data include the possibility of subjective influence (e.g. In biographies), poor validity (e.g. Trying to force data to fit the research when it was collected for a different purpose) and low quality (e.g. Unofficial statistics which have not been independently verified). These can all detract from the accuracy of the research so should be taken into account when choosing your method of data collection.
Data collection for research can be time-consuming and expensive so using existing, or secondary, data can be a cost-effective alternative. However, high quality research does still need a methodical approach so you should ensure the secondary data is accurate, still valid depending on how long ago it was collected, from a reliable and identified source and appropriate to your research.
Secondary data may be qualitative (descriptive) or quantitative (numerical). Qualitative data sources include newspapers, books, diaries, interview transcripts, etc., and quantitative sources typically include surveys and statistics, many of which are available from the public records office or the national archives.
Although a researcher does not actually collect secondary data, it is important to understand the collection method used in the primary instance. A systematic researcher should check the source of the original research thoroughly and be aware of any reasons that may limit its usefulness.
Problems with using secondary data include the possibility of subjective influence (e.g. In biographies), poor validity (e.g. Trying to force data to fit the research when it was collected for a different purpose) and low quality (e.g. Unofficial statistics which have not been independently verified). These can all detract from the accuracy of the research so should be taken into account when choosing your method of data collection.
