response rate in a survey

The response rate in a survey is simply the percentage of people in the sample who actually completed the survey. Thus, if you mail 1,000 questionnaires to a random sample of adults in your community and 500 are completed and returned to you, the response rate is 50%. Response rate is important because it indicates how much bias there might be in the final sample of respondents. Nonrespondents may differ from respondents in any number of ways, including age, income, marital status, and education. The lower the response rate, the greater the likelihood that such biases may distort the findings and in turn limit the ability to generalize the findings to the population of interest.

In general, mail surveys have lower response rates than telephone surveys. With both methods, however, steps can be taken to maximize response rates. With mail surveys, an explanatory postcard or letter can be sent a week or so prior to mailing the survey. Follow-up reminders and even second mailings of Page 155the questionnaire are often effective in increasing response rates. It often helps to have a personally stamped return envelope rather than a business reply envelope. Even the look of the cover page of the questionnaire can be important (Dillman, 2000).

With telephone surveys, respondents who are not home can be called again and people who cannot be interviewed today can be scheduled for a call at a more convenient time. Sometimes an incentive may be necessary to increase response rates. Such incentives can include cash, a gift, or a gift certificate for agreeing to participate. A crisp dollar bill “thank you” can be included with a mailed questionnaire. Other incentives include a chance to win a prize drawing or a promise to contribute money to a charity. Finally, researchers should attempt to convince people that the survey’s purposes are important and their participation will be a valuable contribution.