Primary data is that which is collected by sociologists themselves during their own research using research tools such as experiments, survey questionnaires, interviews and observation.
Primary data can take a quantitative or statistical form, e.g. charts, graphs, diagrams and tables. It is essential to interpret and evaluate this type of data with care. In particular, look at how the data is organised in terms of scale. Is it organised into percentages, hundreds, thousands, etc.? Is it a snapshot of a particular year or is it focusing on trends across a number of years?
Primary data can also be qualitative, e.g. extracts from the conversations of those being studied. Some researchers present their arguments virtually entirely in the words of their subject matter. Consequently the data speaks for itself and readers are encouraged to make their own judgements.