The researcher and the respondents do not come in contact with each other if this method of survey is adopted Questionnaires are mailed to the respondents with a request to return after completing the same. It is the most extensively used mood in various economic and business surveys. Before applying this methods usually a pilot study for testing the questionnaire is conducted which reveals the weaknesses if any of the questionnaire. Questionnaire to be used must be prepared very carefully so that it may prove to be effective in collecting the relevant information.