Written-postal surveys.

The written-postal method is suitable for surveying a large amount of data (more than 100 questions) as for example surveys on differentiated topics or a big variety of subjects. The special layout of the questionnaire and the employment of stimuli provoke rates of return between 40 and 50 percent presenting a basis for representative interpretation.

The advantages of written surveys are that informants can time their participation in the survey individually and that comprehensive material like graphs or complex information can be included in the mail. Besides that, written surveys especially qualify for sensitive issues that should be handled with high anonymity requirements.