Primary and Secondary Data
Primary data — information observed or collected directly from first-hand experience. Data that has been collected by the researcher for the study currently being undertaken, specifically relating to the aims and/or hypothesis of the study. Examples of primary data are the results of an experiment, answers from a questionnaire etc.
(+) Researcher has control over the data, data collection can be designed specifically to the aim.
(-) Collecting primary data is lengthy and expensive.
Secondary data — information that was collected for a purpose other than the current one. Examples of secondary data are government statistics, results from another experiment by the same or different researcher etc.
(+) Cheap to use, no need to set up data collection.
(-)Data might not exactly fit the needs of the study.
A statistical technique for combining the findings of several studies of a certain research area. No additional research is carried out, data from previously conducted research is collected and analysed.