Department of Psychology, Southern Methodist University, Dallas, TX, USA.
Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Med Decis Making. 2018 Aug;38(6):673-682. doi: 10.1177/0272989X18785159. Epub 2018 Jul 2.
"I don't know" (DK) responses are common in health behavior research. Yet analytic approaches to managing DK responses may undermine survey validity and researchers' ability to interpret findings.
Compare the usefulness of a methodological strategy for reducing DK responses to 3 analytic approaches: 1) excluding DKs as missing data, 2) recoding them to the neutral point of the response scale, and 3) recoding DKs with the mean.
We used a 4-group design to compare a methodological strategy, which encourages use of the response scale after an initial DK response, to 3 methods of analytically treating DK responses. We examined 1) whether this methodological strategy reduced the frequency of DK responses, and 2) how the methodological strategy compared to common analytic treatments in terms of factor structure and strength of correlations between measures of constructs.
The prompt reduced DK response frequency (55.7% of 164 unprompted participants vs. 19.6% of 102 prompted participants). Factorial invariance analyses suggested equivalence in factor loadings for all constructs throughout the groups. Compared to excluding DKs, recoding strategies and use of the prompt improved the strength of correlations between constructs, with the prompt resulting in the strongest correlations (.589 for benefits and intentions, .446 for perceived susceptibility and intentions, and .329 for benefits and perceived susceptibility).
This study was not designed a priori to test methods for addressing DK responses. Our analysis was limited to an interviewer-administered survey, and interviewers did not probe about reasons for DK responses.
Findings suggest that use of a prompt to reduce DK responses is preferable to analytic approaches to treating DK responses. Use of such prompts may improve the validity of health behavior survey research.
“不知道”（DK）的回答在健康行为研究中很常见。然而，分析方法处理 DK 回答可能会破坏调查的有效性和研究人员解释发现的能力。
将减少 DK 回答的方法策略与 3 种分析方法进行比较：1）将 DK 视为缺失数据，2）将其重新编码为反应量表的中性点，3）将 DK 重新编码为平均值。
我们使用 4 组设计比较了一种方法策略，该策略在初始 DK 回答后鼓励使用反应量表，与 3 种分析处理 DK 回答的方法进行比较。我们检查了 1）该方法策略是否降低了 DK 回答的频率，以及 2）该方法策略与常见的分析处理方法相比，在构建体测量之间的关联的因子结构和强度方面的比较。
提示减少了 DK 回答的频率（164 名未提示参与者中有 55.7%，而 102 名提示参与者中有 19.6%）。因子不变性分析表明，所有结构的因子负荷在各组中均等效。与排除 DK 相比，重新编码策略和使用提示提高了结构之间关联的强度，提示产生了最强的关联（益处和意图为.589，感知易感性和意图为.446，益处和感知易感性为.329）。
本研究并非旨在预先测试处理 DK 响应的方法。我们的分析仅限于访谈者管理的调查，访谈者没有探究 DK 响应的原因。
研究结果表明，使用提示来减少 DK 响应优于分析方法处理 DK 响应。使用此类提示可以提高健康行为调查研究的有效性。
