In recent years, the number of surveys, especially online surveys, has increased dramatically. Due to the absence of interviewers in this survey mode (who can motivate the respondents to continue answering), some researchers and practitioners argue that online surveys should not be longer than 20 min. However, so far, there has been little research investigating how long respondents think that online surveys should or could be. In this study, we therefore asked respondents of two online panels in Germany (one probability-based panel and one nonprobability panel) about their opinions on the ideal and maximum lengths of surveys. We also investigated whether socio-demographic, personality-related, and survey-related variables were associated with the ideal and maximum lengths reported by respondents. Finally, we compared the stated and observed survey lengths to evaluate the extent to which respondents are able to accurately estimate survey length. Our results suggest that the ideal length of an online survey is between 10 and 15 min and the maximum length is between 20 and 28 min, depending on the measure of central tendency (mean or median) used and the panel. Moreover, we found significant effects of socio-demographics (gender, age, education, and number of persons in household), of personality traits, and survey-related questions (whether the respondents liked the survey, found it easy, and answered from a PC) on at least one of the dependent variables (ideal or maximum lengths). Finally, we found only small differences (less than two min) between stated and observed lengths.

中文翻译：

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受访者认为在线调查应该持续多久？来自德国两个在线小组的新证据

近年来，调查，尤其是在线调查的数量急剧增加。由于这种调查模式没有采访者（可以激励受访者继续回答），一些研究人员和从业者认为在线调查不应超过20分钟。然而，到目前为止，很少有研究调查受访者认为在线调查应该或可能持续多长时间。因此，在本研究中，我们询问了德国两个在线小组（一个基于概率的小组和一个非概率小组）的受访者对理想和最长调查长度的看法。我们还调查了社会人口统计、个性相关和调查相关变量是否与受访者报告的理想和最大长度相关。最后，我们比较了陈述和观察到的调查长度，以评估受访者能够准确估计调查长度的程度。我们的结果表明，在线调查的理想长度在 10 到 15 分钟之间，最大长度在 20 到 28 分钟之间，这取决于所使用的集中趋势（平均值或中位数）的度量和面板。此外，我们发现社会人口统计学（性别、年龄、教育和家庭人数）、性格特征和与调查相关的问题（受访者是否喜欢调查、发现它是否容易，以及从PC）上至少一个因变量（理想或最大长度）。最后，我们发现规定长度和观察长度之间只有很小的差异（小于两分钟）。