Mixed-mode surveys need to determine a number of design parameters that may have a strong influence on costs and errors. In a sequential mixed-mode design with web followed by telephone, one of these decisions is when to switch modes. The web mode is relatively inexpensive but produces lower response rates. The telephone mode complements the web mode in that it is relatively expensive but produces higher response rates. Among the potential negative consequences, delaying the switch from web to telephone may lead to lower response rates if the effectiveness of the prenotification contact materials is reduced by longer time lags, or if the additional e-mail reminders to complete the web survey annoy the sampled person. On the positive side, delaying the switch may decrease the costs of the survey. We evaluate these costs and errors by experimentally testing four different timings (1, 2, 3, or 4 weeks) for the mode switch in a web–telephone survey. This experiment was conducted on the fourth wave of a longitudinal study of the mental health of soldiers in the U.S. Army. We find that the different timings of the switch in the range of 1–4 weeks do not produce differences in final response rates or key estimates but longer delays before switching do lead to lower costs.

中文翻译：

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在顺序混合模式测量中定时模式切换

混合模式调查需要确定一些可能对成本和错误有很大影响的设计参数。在网络后接电话的顺序混合模式设计中，这些决定之一是何时切换模式。网络模式相对便宜，但产生较低的响应率。电话模式是对网络模式的补充，因为它相对昂贵但产生更高的响应率。在潜在的负面后果中，如果预通知联系材料的有效性因更长的时间延迟而降低，或者如果为完成网络调查而额外的电子邮件提醒惹恼了抽样对象，则延迟从网络到电话的转换可能会导致较低的响应率。人。从积极的方面来看，延迟转换可能会降低调查成本。我们通过在网络电话调查中对模式切换的四种不同时间（1、2、3 或 4 周）进行实验测试来评估这些成本和错误。该实验是在美国陆军士兵心理健康纵向研究的第四波中进行的。我们发现 1-4 周范围内的不同转换时间不会产生最终响应率或关键估计的差异，但转换前更长的延迟确实会降低成本。