In order to be able to make a general point a sample group as big and as representative possible ha to be interviewed. This quantitative survey can happen oral (e.g. in the form of standardized telephone interviews) or written (e.g. with the help of online questionnaires). Questions and answers are fixed in the survey and may not be changed in order to ensure comparability. This means that for every question all possible answers have to be known in advance. The subsequent evaluation is supported by special evaluation software.
With quantitative surveys hypothesis and results (e.g. from __ qualitative interviews__) can be checked. Moreover they allow deriving general statements regarding the requirements of users. The given answer options allow comparing and objectively measuring the data of multiple interviewees. With this it is possible to reveal statistic connections between single variables and read developments.