Advantages of questionnaires include the ability to access a large sample and, if using largely closed questions, the ability to generate a large amount of quantitative data that can be analysed easily. Of course, for the data to be analysed easily, the questionnaire needs to have been well designed (this can be tested with a pilot study). It is also possible to achieve some triangulation with this method without having to combine with other methods, because using a mixture of open and closed questions can provide a combination of quantitative and qualitative data (although the latter can be more difficult to analyse). This method is usually considered to be reliable because everyone is responding to the same questions, although this is less true if the questions are open as everyone might interpret them differently.

Disadvantages of this method include the danger of a poor response rate if the survey is not administered in person. Also, even though they might produce some qualitative data, they are generally considered to produce data that is not especially valid as there is unlikely to be significant detail or opportunities for verstehen.