Even the most carefully crafted questionnaire cannot yield reliable results if the response rate is lacking in some way. The tendency of individuals to complete a questionnaire can be modified using a variety of methods. A list of several of such options can be found below.
Pre-mails: Whenever possible, provide the sample population with advanced notice via mail or email that they should expect to be contacted for the purposes of completing a questionnaire. This is particularly effective if an exact date can be specified in the pre-mail, as it allows those who are interested in participating to actively watch their email and/or mail, or keep themselves available for a phone call. The pre-mail also gives you an opportunity to increase the motivation of the sample population to complete the questionnaire by making a substantive case for its importance and communicating a sense of urgency for completion by detailing the window of time being made available for doing so (see “usefulness of results” and “window of time” below).
Reminders: While disinterest plays a role in low response rates, so too does forgetfulness. Busy schedules, full inboxes, and a plethora of junk-mail can cause a request to complete a questionnaire to become physically and mentally lost. Reminders are an excellent way to combat this problem, particularly when they include a copy of, or a link to, the questionnaire which precludes the potential respondent from having to search for the original invitation. However, it is important to be conservative in the use of reminders. Sending more than one per week threatens to transform helpful and friendly reminders into annoying and nagging messages. The salience of reminders can be increased if they are sent from figures the sample population will perceive as being influential (see “involvement of influential figures” below).
Window of time: Though windows of time are more of an indirect means of impacting response rates, two contradictory methods have the potential to garner more responses: limiting windows and extending windows. When first contacting the sample population about a questionnaire, it is important to give them a multitude of reasons to make responding a top priority. To that end, a limited window, which provides the sample population no more than three or four weeks to respond, can be useful. This helps combat the tendency to put off until tomorrow what does not need to be done today. Alternatively, the ability to extend the window of a questionnaire after the administration has begun can improve the response rate. Assuming that the original window was simply poorly timed for the sample population, extending the window (and providing a rationale and encouragement for completion via a reminder) can allow those who were interested, but unable to complete the questionnaire in the original window of time, the opportunity to do so.
Usefulness of results: With questionnaires becoming more commonplace, it is important to provide the sample population with a plethora of reasons to perceive yours as valuable. By convincing the potential respondents that the results will have a real impact on something they care about, the odds of them choosing to complete the questionnaire is increased. Will your questionnaire improve a service they utilize? Will the results be shown to people of perceived importance? Make sure that your sample population is aware that the results will do more than sit on a bookshelf.
Involvement of influential figures: While this website has spoken extensively about making the content of your questionnaire compelling, there are times when the individual who asks the sample population to complete the questionnaire provides a crucial element of motivation. Is there a particular individual, or set of individuals, whose opinion is of great importance to your sample population? If so, convincing them to write in support of your questionnaire can be very beneficial. If you are lucky to have more than one influential figure to utilize, assigning them each to separate reminders increases the effectiveness of those reminders.
Incentives: In the contest for attention and time, researchers are increasingly turning to the use of incentives. Literature on the topic suggests that, while incentives are an effective means of increasing response rates, not all incentives are created equal. Incentives that are given unconditionally to potential respondents may be more effective than those that are conditional upon the completion of the questionnaire. Additionally, though incentives may increase response rates, it often requires asking respondents for identifying information, a practice which often decreases the willingness of potential respondents to complete a questionnaire.
Other Online Resources
How Often Should You Send Survey Reminders? (LearningBridge)
Using Incentives in Survey Research (StatPac)
Benefits and Weaknesses of a Pre-Survey Incentive (Survey Methods)
10 Easy Ways to Increase Response Rates for your Online Survey (QuestionPro)
Further Reading
Nulty, D.D. (2008). The adequacy of response rates to online and paper surveys: What can be done? Assessment & Evaluation in Higher Education, 33(3) 301-314.
Suskie, L.A. (1996). Questionnaire survey research: What works (2nd ed.). Tallahassee, FL: Association for Institutional Research