Data can be obtained from previously published books, newspapers, magazines, journals, websites, etc., or can be gathered during a live test, experiment or user trial, for example.

Data collection methods can produce quantitative or qualitative data.

Quantitative data collection methods are objective and are based on calculations and analysis of the results of, for example, questionnaires with closed-ended questions, measurements and statistics. Quantitative data can often be quick and cheap to gather compared to qualitative methods. And because of standardisation of quantitative methods, you can easily compare findings.

Qualitative data collection often involves more subjective information such as words, sounds, feelings and emotions that are non-quantifiable. However, these types of study can result in a greater depth of understanding. Methods include interviews, questionnaires with open-ended questions, focus groups, observations, etc.

The choice between quantitative or qualitative methods of data collection depends on the area of research and its aims and objectives.