Public opinion surveys on American foreign policy often elicit many "don't know" or "no opinion" responses. Researchers have paid surprisingly little attention to these responses, typically dropping them from their analyses or suppressing them in the survey design. We argue that these practices lead to potentially misleading conclusions about both the level of support for particular foreign policies and the determinants of individual attitudes. We demonstrate these problems using an original survey experiment testing the effect of including a DKNO option on three common questions about international trade, the use of force, and isolationism. Our findings also suggest that taking DKNO responses more seriously in our analyses provides a richer sense of the process through which important covariates actually influence attitudes.

中文翻译：

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对外交政策知之甚少：评估“不知道”和“无意见”回应对外交政策态度推断的影响

对美国外交政策的民意调查经常会引出许多“不知道”或“没有意见”的回答。令人惊讶的是，研究人员很少关注这些反应，通常将它们从分析中排除或在调查设计中压制它们。我们认为，这些做法可能会导致关于对特定外交政策的支持水平和个人态度决定因素的误导性结论。我们使用原始调查实验来证明这些问题，该实验测试了包括 DKNO 选项对有关国际贸易、使用武力和孤立主义的三个常见问题的影响。