A recent meta-analysis of the response rates in 19 multi-modal surveys offering mail and web options indicated that a concurrent web option significantly lowered overall response

rates (Medway and Fulton, POQ, Winter 2012). The impact of sequential or simultaneous multi-modal survey approaches was analyzed by comparing results from the two most recent waves of a residential appliance saturation survey conducted for Southern Company. The survey, which is conducted at three-year intervals, was conducted in 2010, and data collection for the 2013 survey wave has just been completed, with samples of 15,000 randomly-selected customers in each wave. The following data collection approaches were used in the two survey waves:

 Simultaneous multi-mode: In 2010, the cover letters transmitting the original mail survey provided a URL and password at which the potential respondent could access the survey

online, rather than returning it by mail. This information was also included in a second mailing of the questionnaire to non-respondents.

 Mixed sequential/simultaneous multi-mode: In 2013, the survey began with an email invitations to approximately one-half of respondents for whom email addresses were available. A reminder email was sent several days later. Subsequently, mail survey packets were sent to all non-respondents, including both those who had and had not received the email invitation. The URL and a password to access the survey were included in both the initial and reminder cover letters for the mail survey.

There was an increase in the number of web surveys completed in 2013 compared with 2010 (703 and 476, respectively). However, the overall response rate decreased from 36.9% in 2010 to 29.9% in 2013. We are currently