Qualitative data are often called 'soft' data, in that they describe subjective human perspectives on a topic or theme. Qualitative methods are in a way behavioural. They used where researchers need to examine how and more importantly, why individuals see and experience the world in the way they do. Qualitative data can be used to give meaning to phenomena, and to identify recurring patters of behaviour, interpret those behaviours, and predict trends in behaviour over time.
Because qualitative data collection usually involves direct interaction on part of the researcher with their subject, these types of research often require ethical approval.
Qualitative collection methods include;
Interviews: An unstructured (or structured) conversation;
Focus Groups: An interview that takes place with a group of people;
Content Collection: where data is collected through systematically searching through documents and records; and
Ethnography: the collection of data about people through detailed observation.
Quantitative data are often numerical, the advantage being the statistical analysis that you can apply. Because numbers are objective they be used to derive definitive conclusions about a particular problem or issue. Quantitative data are usually used to answer questions about what or who is involved in a particular issue and are used to;
Quantitative data doesn't always start life as a set of numbers. For example, observing the frequency of an event, or coding an observation against a scale. Whether or not this kind of conversion of data will be useful depends on you as a researcher, the types of observations you’re recording, and your overall research objective. Quantitate collection methods include;
Field Observations: data collection by close attention to what is happening in a given setting;
Interviews: where data is gathered through structured (or unstructured) conversation;
Questionnaires: structured data collection using a a set of questions and their corresponding response categories; or
Measurements: where data is collected by comparing an event or object against a valued scale.