Data, sampling and errors
1. Primary and secondary data sources
There is a range of data sources available to you. The diagram below shows some of them as well as the effort required to obtain them. For example, primary sources require measurement to obtain data, whereas secondary sources provide an available source of ready data for you to analyse. Sources of secondary data can further be broken down into internal and external data sources.
We will look further at primary and secondary data in Unit 5.