Empirical research projects are divided into qualitative and quantitative methods.
Characteristics of the qualitative approach
Statements, attitudes and opinions are recorded by hermeneutic, but also by narrative and other methods in order to make their meanings usable.
This usually happens with a small number of cases, because qualitative interviews, for example, which consist of open questions and thus sometimes far-reaching answers, are obtained where they are meaningful; frequencies of the same or similar answers usually do not play the main role.
It is a similar procedure as with the scientific literature: one looks for statements that could be used as arguments.
Characteristics of the quantitative approach
Only that which is countable, measurable or collectable is recorded by surveys or measurements. The aim here is to generate data that can be statistically evaluated.
In the social sciences, the representativeness of quantitative results is important; therefore, a sample is defined in relation to a population and, as a rule, significantly higher case numbers are required for the study than for the qualitative approach.
Quantitative interviews or surveys do not consist of open questions, but of closed questions: respondents can only provide standardised information.
It makes sense and is quite customary to add at least one open question here in order to be brought in this way - without statistical possibilities of use - to other and new aspects which would not be in view in a strictly closed survey.