8.1 Although it would be impossible to list all possible situations, the key features that should appear in your examples are listed below: • to compare findings from your primary data; • to place findings from your primary data in a wider context; • to triangulate findings from other data sources; • to provide the main data set where you wish to undertake research over a long period, to undertake historical research or to undertake comparative research on a national or international scale with limited resources.