Mail Studies -- The Total Design Method
When Is A Mail Study Appropriate?
Mail studies have traditionally been used as an alternative to telephone and in-person surveys, when the information being gathered requires more respondent time and thought than is practical over the phone, or when physical materials must be presented to the respondent (e.g., printed product brochure, a copy of an advertisement, etc.). Mail studies can be the best methodology when trying to communicate with large, specifically targeted, geographically dispersed respondents, especially when significant segmentation is needed. As the sample size increases to 1,000 or more, mail studies are usually more cost effective.Web-based Online Research or "Web Surveys" are the modern equivalent of the mail methodology and provide the opportunity for far superior quality controls. We recommend the use of Market Decision's Web Survey technology however, mail studies can still be the best choice when Internet penetration among the targeted audience makes a web survey inappropriate, or when access to e-mail addresses is a barrier. A Phone / Web Hybrid study can also be considered.
The "Total Design Method" We Employ
The Total Design Method (TDM) is the specific mail study technique that Market Decisions uses in order to maximize response rate and enhance the quality of mail study data. The workflow process and design recommendations presented herein are based on "Mail and Telephone Surveys -- The Total Design Method," by Don A. Dillman, and Market Decisions Corporation's experience using this research technique, first introduced in 1978.Used properly, TDM will generate up to an 80% response rate among the general population and most professional research audiences. TDM's basic premise is that a successful project (i.e., high data quality and return rate), depends on attention to detail and quality of the survey design and instruments.
We achieve the highest possible quality by applying these basic tenets:
- Make the survey important. Care must be taken to avoid a "junk mail" perception. Emphasis needs to be placed on the value of the information being collected and its uses, in terms of benefits to the survey target audience. A token incentive helps demonstrate the importance of the study. Incentive options include: a drawing for a merchandise prize; donations to charity in the respondent's or company's name; or the inclusion of a $5 bill in the initial mailing piece.
- Make the respondents feel important. Personalizing the communications wherever possible will help break down response barriers. Stress the value and importance of the respondent's personal opinions. Use the respondent's first and last name on the cover letters and envelopes and hand sign the letters. Avoid the use of "bulk-mail" type mailing labels.
- Make completing the survey an easy task. If the respondent has to "work" to complete the survey, response rates will decline. Questions must be formatted for clarity and intuitive implementation. The questionnaire itself should be kept as short as possible. Pre-addressed business reply envelopes must be included and the questionnaires should fit easily into the envelope.
- Multiple Mailings. The standard TDM study uses three separate mailings, with an option for a fourth.
TDM Mailing Schedule
- First Mailing: The initial Tuesday mailing to all respondents includes a cover letter, business reply envelope, incentive and questionnaire.
- Second Mailing: Exactly one week after the initial mailing, a reminder postcard is sent to all respondents, asking them to complete and return the survey, if they have not already done so.
- Third Mailing: Exactly three weeks after the initial mailing, a third mailing (replicating the initial mailing) is sent to those who have not yet returned their questionnaire.
- Fourth Mailing: If the return rate is not acceptable, an optional final attempt to gather information is mailed on Tuesday, five to six weeks after the initial mailing. This mailing is often sent by registered mail or some other "urgent" communications technique (fax, Express Mail, Federal Express, UPS, etc.).
Why Mail on Tuesdays?
Tuesday mailings help reduce competition with mail sent on the two busiest mail days (Monday and Friday). Respondents receive the questionnaire the same week it is sent and return it before, or over, the weekend. Since follow-up mailings are dropped at the Post Office the same day of the week for each mailing, the weekend returns will have been received by Tuesday, eliminating costly duplicate mailings.TDM Questionnaire Format
The second most-important task is to develop a solid communications piece. A TDM questionnaire is formatted in a carefully designed booklet format.- The TDM booklet is 7" x 8 1/2". This size is big enough to present material, without appearing overwhelming to a respondent. It "reduces" the perceived size of the research task.
- The front of the TDM questionnaire booklet is reserved specifically for material designed to stimulate interest in the questionnaire. The front cover should never be used for the cover letter; it is an important, separate element