應用信號偵側理論評估介面複雜度對視覺搜尋表現之影響

Abstract

隨著高科技的發展, 電腦介面設計已不可避免地有愈來愈複雜的趨勢,受限於使用者 的訊息處理的能力, 複雜度 (complexity) 對使用者使用效率的影響已成為近年介面 設計的一個重要考量。Xing (2004) 提出複雜度有三個基本向度, 數量 (numeric size), 變化性 (variety), 規則或關係 (rule or relation)。更進一步她建議這三個複雜度的基 本向度可以在訊息處理的三個主要階段, 知覺, 認知, 及行為反應上分別加以評量。 本研究旨在探討知覺上的三個複雜向度, 螢幕上的刺激數量, 顏色種類, 及背景擁擠 程度 (clutter) 對使用者視覺搜尋表現的影響。本研究使用信號偵測理論方法 (signal detection theory methodology)進一步探討知覺複雜度的影響主要是在於視覺搜尋中 使用者的知覺敏感度 (perceptual sensitivity)或是決策標準 (decision criterion)。本實 驗採取視覺搜尋作業, 受測者需在很短的時間內在電腦桌面中儘快地搜尋指定的目 標物而做出目標物存在或不存在的判斷。做完判斷之後受測者將進一步對他們所做 的判斷做信心程度的評量 (confidence rating)。主要的測量包括反應時間, 正確率, 命 中率(hit rate) , 假警報率(false alarm rate) 及信號偵測理論的測量 d’,β及ROC (receiver operating characteristics)。經由了解知覺複雜度對使用者敏感度 (perceptual sensitivity)或是決策標準(decision criterion)的影響, 本研究將對介面設計提供有效的 建議。

Advanced technology has enabled us to present ample and multifaceted information on computer-based interface systems. However, the more do not mean the better. Human information processing capacity is limited and thus the demands of a highly complex interface system may eventually exceed the user’s processing capacity and deteriorate task performance. Complexity therefore becomes a critical issue in interface design. Xing (2004) proposed that numeric size, variety, and relation or structural rule are the three basic factors that determine the system complexity. She further suggested that those three complexity factors need to be evaluated at each of the three stages of information processing, perception, cognition, and action. The goal of the present study is to evaluate the impacts of the three perceptual complexity factors (number of items, color variety, and background clutter level on the display) on the user’s visual search performance within a computer display. Particularly, the present study employs signal detection theory methodology to further examine the effects of perceptual complexity on the user’s perceptual sensitivity and decision criterion in detecting a target. A speeded visual search task is adopted where participants will search among alternatives and decide whether the target is present as quickly as possible within a brief period of time. Reaction time, response accuracy, hit rate, false alarm rate, and signal detection measures d’ and β, and the ROC curve will be measured and derived. Understanding the impacts of perceptual complexity on the user’s sensitivity and decision criterion during visual search will provide us with more insights into the designing of more effective and user-friendly interface systems.