Documents, official statistics and secondary analysis: mining existing data sources
Clearly, primary research is only really necessary when suitable existing data are not available,
and there would thus seem to be a strong case for carrying out a 'data review' alongside the literature review that a researcher typically carries out. How-
The various forms of existing data are used more frequently than a novice researcher might expect, given their lack of prominence in methods texts and teaching. However, that very lack of prominence may in part explain why researchers often fail to exploit fully, and are sometimes unaware of,
Later in a research project, once any primary data have been collected, existing data may serve
While existing data from a single source will on occasions provide the empirical core of a research project, very often existing data are used in combination with primary data, or existing data from different sources (or of different kinds) are pooled together. Comparisons of data from different sources may reveal reassuring similarities or highlight interesting inconsistencies; the aggregation of data from different sources may help the researcher build up a fuller or more balanced picture of the social phenomenon of interest to them.