School of Management and Institute for Health and Social Science Research, Central Queensland University, Rockhampton, Queensland, Australia.
Chronobiol Int. 2011 Feb;28(1):81-7. doi: 10.3109/07420528.2010.502603.
The Circadian Amplitude and Phase Scale (CAPS) is a new self-report tool that aims to assess amplitude and phase. The CAPS consists of three factors made up of 38 items. Amplitude is posited to be assessed via two of these factors: time awareness (TA) and/or strength of preference (SOP). The remaining factor, phase, is assessed via the existing Preferences Scale (PS). Given there is no published research using this measure, the authors undertook two studies to examine its psychometric properties and construct validity. In a sample of 351 North American students, the authors identified a three-factor 34-item model using principal components analysis. The components explained 39% of the variance, and scale reliability ranged from 0.73 (SOP) to 0.88 (PS). The correlations between the components were small, suggesting they are each assessing different constructs. Thus, it is unlikely TA and SOP may both be indicators of amplitude. The distributions for each scale were divided into two groups (≤ 25th and ≥ 75th percentiles), and these groups were used to assess construct validity using alertness ratings by time-of-day. The results from a multivariate general linear model indicated a significant difference (p < .001) in sleepiness ratings by time-of-day for the PS scale only. In the second study, the authors applied confirmatory factor analysis in an attempt to replicate the factor structure identified in the student sample in a working sample (n = 388). The results suggested the model fit was not optimal. Subsequent analysis suggested a 26-item model was a better fit, but it also was not optimal. The intercorrelations between the factors were larger than in the student sample but again small, indicating the constructs are independent measures. The inability to replicate the factor structure is most likely explained by the differences in the sample characteristics of age, sex, and perhaps difficulty in interpreting the items. The limitations of these studies are discussed and recommendations for future studies are made.
《生物钟振幅和相位量表（CAPS）》是一种新的自评工具，旨在评估振幅和相位。CAPS 由三个由 38 个项目组成的因子组成。假设通过其中两个因子来评估振幅：时间意识（TA）和/或偏好强度（SOP）。剩余的因子，相位，通过现有的偏好量表（PS）进行评估。由于没有使用该测量方法的已发表研究，作者进行了两项研究来检验其心理测量学特性和构念效度。在 351 名北美学生的样本中，作者使用主成分分析确定了一个三因子 34 项模型。这些成分解释了 39%的方差，量表信度范围从 0.73（SOP）到 0.88（PS）。成分之间的相关性较小，表明它们各自评估不同的结构。因此，TA 和 SOP 不太可能都是振幅的指标。每个量表的分布分为两组（≤第 25 百分位和≥第 75 百分位），并使用日间警觉性评分来评估这些量表的构念效度。多元方差分析结果表明，PS 量表的日间睡眠评分存在显著差异（p<0.001）。在第二项研究中，作者应用验证性因子分析试图在工作样本（n=388）中复制学生样本中确定的因子结构。结果表明，模型拟合不理想。随后的分析表明，26 项模型拟合度更好，但也不理想。因子之间的相互关联大于学生样本，但仍然较小，表明这些结构是独立的测量方法。无法复制因子结构最可能是由于样本特征（年龄、性别）的差异以及对项目的解释难度不同造成的。讨论了这些研究的局限性，并提出了未来研究的建议。
