Any survey technique that requires the respondent to complete the questionnaire him/herself is referred to as a self-administered survey. The most common ways of distributing these surveys are through the use of mail, fax, newspapers/magazines, and increasingly the internet, or through the place of purchase of a good or service (hotel, restaurant, store). They can also be distributed in person, for instance as part of an intercept survey. Depending on the method of survey administration, there are a number of sampling frame considerations, such as who can or cannot be reached by fax or internet, or whether there is a sample bias.
A considerable advantage of the self-administered survey is the potential anonymity of the respondent, which can lead to more truthful or valid responses. Also, the questionnaire can be filled out at the convenience of the respondent. Since there is no interviewer, interviewer error or bias is eliminated. The cost of reaching a geographically dispersed sample is more reasonable for most forms of self-administered surveys than for personal or telephone surveys, although mail surveys are not necessarily cheap.
In most forms of self-administered surveys, there is no control over who actually fills out the questionnaire. Also, the respondent may very well read part or all of the questionnaire before filling it out, thus potentially biasing his/her responses. However, one of the most important disadvantages of self-administered surveys is their low response rate. Depending upon the method of administration chosen, a combination of the following can help in improving the response rate:
- A well written covering letter of appeal, personalized to the extent possible, that stresses why the study is important and why the particular respondent should fill in the questionnaire.
- If respondents are interested in the topic and/or the sponsoring organization, they are more likely to participate in the survey; these aspects should be stressed in the covering letter
- Ensuring confidentiality and/or anonymity, and providing the name and contact number of the lead researcher and/or research sponsor should the respondent wish to verify the legitimacy of the survey or have specific questions
- Providing a due date that is reasonable but not too far off and sending or phoning at least one reminder (sometimes with another survey, in case the original one has been misplaced)
- Follow-up with non-respondents
- Providing a postage paid envelope or reply card
- Providing an incentive, particularly monetary, even if only a token
- A well designed, visually appealing questionnaire
- A shorter questionnaire, where the wording of questions has been carefully considered. For instance, it might start with questions of interest to the respondent, while all questions and instructions are clear and straight forward
- An envelope that is eye-catching, personalized and does not resemble junk mail
- Advance notification, either by phone or mail, of the survey and its intent