Sample size for pre-tests of questionnaires
Sample size for pre-tests of questionnaires
复制标题
DOI：
10.1007/s11136-014-0752-2
复制
发表时间：
2015-01-01
影响因子：
3.5
通讯作者：
Gayet-Ageron, Angele
中科院分区：
文献类型：
--
作者：
Perneger, Thomas V.;Courvoisier, Delphine S.;Gayet-Ageron, Angele
当预测试的目的是检测参与者可能遇到的工具项目的误解、歧义或其他困难时，就心理测量问卷预测试的理想规模提供指导（称为A >）。我们计算了（a）检测各种流行程度和各种样本大小的问题的能力，（B）在不同的普遍程度下发现问题所需的样本量，以及（c）在没有发现问题的情况下，问题普遍程度的置信上限。正如预期的那样，功效随着问题普遍程度和样本量的增加而增加。如果问题流行率为0.05，则10名参与者的样本只有40%的把握度来检测问题，而20名参与者的样本达到了64%的把握度。为了达到80%的功效，如果问题的患病率为0.05，则需要32名参与者，如果患病率为0.10，则需要16名参与者，如果患病率为0.20，则需要8名参与者。如果在给定的样本中没有观察到问题，则样本量为10的双侧90%置信区间的上限达到0.26，样本量为20的双侧90%置信区间的上限达到0.14，样本量为30的双侧90%置信区间的上限达到0.10。在问卷的预测试中常见的小样本（5-15名参与者）可能无法发现甚至常见的问题。建议默认样本量为30名参与者。
To provide guidance regarding the desirable size of pre-tests of psychometric questionnaires, when the purpose of the pre-test is to detect misunderstandings, ambiguities, or other difficulties participants may encounter with instrument items (called A >).We computed (a) the power to detect a problem for various levels of prevalence and various sample sizes, (b) the required sample size to detect problems for various levels of prevalence, and (c) upper confidence limits for problem prevalence in situations where no problems were detected.As expected, power increased with problem prevalence and with sample size. If problem prevalence was 0.05, a sample of 10 participants had only a power of 40 % to detect the problem, and a sample of 20 achieved a power of 64 %. To achieve a power of 80 %, 32 participants were necessary if the prevalence of the problem was 0.05, 16 participants if prevalence was 0.10, and 8 if prevalence was 0.20. If no problems were observed in a given sample, the upper limit of a two-sided 90 % confidence interval reached 0.26 for a sample size of 10, 0.14 for a sample size of 20, and 0.10 for a sample of 30 participants.Small samples (5-15 participants) that are common in pre-tests of questionaires may fail to uncover even common problems. A default sample size of 30 participants is recommended.