Study of Internet Web Contents Design Based on Cognitive Engineering Principles

本研究探讨了网页的背景颜色、标签和图形上下文等网页属性对可用性的影响，并考察了它们对可用性的影响程度。此外，还提出了作为网页可用性衡量指标之一的脑力劳动负荷的评价方法。本研究的研究结果总结如下：1.在多窗环境下，周边窗与中心凹窗的面积比是影响视觉干扰的决定性因素之一。此外，视觉干扰不是发生在知觉过程中，而是发生在认知过程中。文本标签和图形上下文对图形用户界面中的图标理解有效。标签与语境在整体效应上没有太大差异，但图形语境对高复杂度图标的影响要强于标签。提出了两种基于脑电(EEG)信号小波变换和基于心率变异性(HRV)的VDT任务脑力负荷(MWL)评估方法。建议的EEG和HRV指标随着工作负荷水平的变化而变化，可以可靠地评估VDT任务中的MWL。为了评估基于显示布局属性的屏幕可用性，我们考察了屏幕复杂性对搜索时间和主观评价的影响。实验结果表明，大小、局部密度、排列和分组等四个实验因素对屏幕可用性有显著影响。其中，对齐和分组对可用性影响较大。从准则中选取网页布局的固有属性作为影响可用性的因素，考察了搜索时间、主观评价等因素对可用性的影响。

In this study, some attributes of web pages effecting its usability, like the background color, labels and graphical contexts of windows, were discussed, and the degree of their effectiveness for the usability was investigated. Moreover, the evaluation method for the mental workload, which was regarded as one of the measures of the web page usability, was proposed. The results of this study was summarized as follows.1. In the multi-windows setting, the area ratio of the peripheral window to the foveal window was one of the determinant factors that affected the visual interference. Moreover, the visual interference occurred not during the perceptual process, but during the cognitive process.2. The textual label and the graphical context were effective for the icon comprehension in GUI. There did 'not exist much difference on the effect between the label and the context as a whole, but the graphical context effected the comprehension of high complex icons more strongly than the label.3. We proposed two evaluation methods for the mental workload (MWL) during VDT tasks based on the wavelet transform of EEG (Electroencephalogram) signal or HRV (Hear rate variability). The proposed indices of EEG and HRV changed in accordance with the change of the workload level, which could reliably evaluate the MWL during VDT tasks.4. We investigated the effect of screen complexity on search time and subjective evaluation in order to evaluate the screen usability based on attributes of display layout. The experiment results showed that the four experimental factors, like size, local density, alignment, and grouping, significantly affected the screen usability. Especially, the alignment and grouping strongly effected the usability.5. The inherent attributes of layout of web pages were selected from the guideline as factors effecting the usability, and the their effect for the usability such as search time and subjective evaluation was investigated.