Determinants of the Starting Rate and the Completion Rate in Online Panel Studies

This review summarizes all of 204 web-based studies that were conducted in a nonprofit online panel spanning an interval of 13 years. Thirty study characteristics were examined as to how they influence panelists´ starting rate and completion rate. These study characteristics pertain to temporal features of the study, attributes of participants invited to the study, panel status at the time the study was conducted and rewards offered for study participation. A higher share of invited panelists called up the first page of a study (a) the fewer panelists that were in the panel in the year of study, (b) the more the panel had grown in the year of study, (c) in the winter, (d) the fewer panelists that were invited to the given study, (e) if the study was an in-house study, (f) if a reminder was sent, (g) if panelists who were invited to the study took part in a previous study, (h) if the length of the study was announced in the study request, (i) the shorter the study and (j) if a per-capita reward was offered. A higher share of responding panelists stayed until the final page of a study (a) the younger a study, (b) the fewer the number of studies are run in the year of study, (c) in seasons other than winter, (d) the longer the time lag to the preceding study, (e) if panelists were invited who took part in a previous study and (f) the shorter the study. Based on these findings, recommendations are made about how to best conduct online panel studies with a view on the starting rate and the completion rate.

本综述总结了在一个非营利性在线面板中开展的、时间跨度达13年的204项基于网络的研究。研究考察了30项研究特征对面板参与者启动率和完成率的影响。这些研究特征涉及研究的时间特征、受邀参与者的属性、研究开展时的面板状态以及参与研究的奖励。受邀面板参与者中访问研究首页的比例更高的情况发生在：(a)研究开展当年面板中的参与者数量越少；(b)研究开展当年面板的增长幅度越大；(c)冬季；(d)受邀参与该研究的面板参与者数量越少；(e)研究为内部研究；(f)发送了提醒；(g)受邀参与研究的面板参与者曾参与过此前的研究；(h)研究时长在研究邀请中已声明；(i)研究时长越短；(j)提供了人均奖励。做出响应的面板参与者中坚持到研究最后一页的比例更高的情况发生在：(a)研究开展时间越晚；(b)研究开展当年运行的研究数量越少；(c)非冬季季节；(d)与前一项研究的时间间隔越长；(e)受邀的是曾参与过此前研究的面板参与者；(f)研究时长越短。基于这些发现，本文提出了着眼于启动率和完成率的在线面板研究最优开展建议。