Cohen D, Wherry R J, Glenn F
Naval Air Warfare Center, Aircraft Division, Warminster, USA.
Aviat Space Environ Med. 1996 Feb;67(2):139-45.
During the design process, operator workload assessments sometimes require subject matter experts (SME's) to predict the amount of physical and mental demands they expect during system employment. Often, these subjective estimates are considered within the context of models that partition human capabilities into discrete resources. Such models require the SME's to rate tasks on how they affect resource consumption. This type of assessment technique is based upon the premise that raters can effectively discriminate their own resources.
Subjective workload ratings based on multiple resource theory were collected independently from two highly experienced pilots for 225 different tasks of an anticipated mission for a future advanced strike aircraft. The data were examined using a factor analytic approach.
Factor analysis of their responses suggest that while such ratings have high face validity and even high inter-rater reliabilities, the ratings could have little validity in terms of efforts required to use the seven postulated resource channels (i.e., visual or auditory input, spatial, verbal or analytical cognition, and manual or speech output). Ratings of efforts required for the cognitive resource channels were particularly suspect. We identified four independent factors for each pilot that accounted for virtually all of the intercorrelations among the 7 resource channels. Three factors (i.e., visual-spatial, verbal communications, and manual and speech output) were identical for both pilots and accounted for most of the explainable variance.
Given these results, this analysis challenges the utility of a multiple resource framework for predictive workload assessments.
在设计过程中，操作人员工作量评估有时需要主题专家（SME）预测他们预期在系统使用期间的身心需求程度。通常，这些主观估计是在将人类能力划分为离散资源的模型背景下进行考虑的。此类模型要求SME根据任务对资源消耗的影响程度进行评分。这种评估技术基于这样一个前提，即评分者能够有效区分自己的资源。
基于多重资源理论的主观工作量评分由两名经验丰富的飞行员独立收集，涉及未来先进攻击机预期任务的225项不同任务。使用因素分析方法对数据进行检查。
对他们回答的因素分析表明，虽然此类评分具有较高的表面效度甚至较高的评分者间信度，但就使用七个假定资源通道（即视觉或听觉输入、空间、语言或分析认知以及手动或语音输出）所需的努力而言，这些评分可能几乎没有效度。认知资源通道所需努力的评分尤其值得怀疑。我们为每位飞行员确定了四个独立因素，这些因素几乎解释了七个资源通道之间的所有相互关系。三个因素（即视觉空间、语言交流以及手动和语音输出）对两名飞行员来说是相同的，并且解释了大部分可解释的方差。
鉴于这些结果，该分析对多重资源框架在预测工作量评估中的效用提出了质疑。
