Prenotification in Web-Based Access Panel Surveys

To compare the effectiveness of different prenotification and invitation procedures in a web-based three-wave access panel survey over 3 consecutive months, we experimentally varied the contact mode in a fully crossed two-factorial design with (a) three different prenotification conditions (mobile short messaging service [SMS], e-mail, no prenotice) and (b) two “invitation and reminder” conditions (SMS, e-mail). A group with nearly complete mobile phone coverage was randomly assigned to one of these six experimental conditions. As expected, SMS prenotifications outperformed e-mail prenotifications in terms of response rates across all three waves. Furthermore, e-mail invitation response rates outperformed those for SMS invitations. The combination of SMS prenotification and e-mail invitation performed best. The different experimental treatments did not have an effect on the sample composition of respondents between groups.