多目標搜尋過程中搜尋策略與策略表現之探討

視覺為外界訊息輸入的主要通道，其於人獲取資訊的過程中扮演著重要的角色。日常生活中有許多任務需仰賴目標搜尋才得以完成，然而由於人的注意力資源有限，當面對大量且複雜的環境時，需將有限的注意力資源運用在與任務相關的資訊上，以提升獲取資訊的效率。透過與目標搜尋相關的文獻發現，多數研究著重探討目標物為單一個的情境，然而於現實環境中，目標物往往不只一個，即使有少數研究探討多目標物的情境，也多傾向於模型的推論與適用性，對於人在多目標物情境下的搜尋行為缺乏深入的探討與剖析。　　因此，本研究以特徵聯結搜尋（Conjunction search）作業作為搜尋的任務，探討在目標物數目為10%、30%、50%、70%、90%的多目標物情境下，觀者的搜尋行為。並根據觀者凝視點的起始位置與視線軌跡移動的方向，提出編碼與歸納眼動路徑的方式，歸納個體所採取的目標搜尋策略。且以作業中正確率、搜尋時間與凝視點數目作為衡量策略表現的指標。　　本研究提出的編碼與歸納方式，足以歸類85%的搜尋路徑，具有良好的適用性與一致性。在多目標物數目的情境中，觀者會採取單一與複合兩種搜尋策略，而單一搜尋策略又可細分成Z、W和O型搜尋模式。研究結果顯示，在目標物數目小於干擾物數目的情境下，採取單一搜尋策略的次數明顯多於複合搜尋策略，且確實在該情況下，單一搜尋策略花費較少的搜尋時間與凝視點數目，表現較佳。

關鍵字

目標搜尋；搜尋策略；多目標物；搜尋表現；眼動

並列摘要

Vision plays an important role in the process of information acquisition. In a daily life, we need to rely on the target search to complete various tasks. However, when facing the complex environments, limited attention need to be applied to the task-related information to improve the efficiency of information acquisition due to the limited attention resources. Through related literature, our study found that most studies emphatically discuss the target for a single situation, but in the real environment, target is often more than one. Even a few researches are about multiple target situation, is more inclined to examine the applicability of the model. There is a lack of in-depth discussion and analysis of human searching behavior in the context of multiple targets. 　　Therefore, in this study, discusses the viewer's search behavior in the case of multiple targets, which the number of the targets is 10%, 30%, 50%, 70% and 90%. According to the starting position of the viewer's fixation and the direction of the eye track movement, the method to code and to summarize the eye movement path is proposed. The target search strategy adopted by the individual is summarized. The accuracy, search time and the number of fixation were used as the indicators to measure the performance of the strategy. 　　The coding methods proposed in this study induced 85% of the search paths, and have good applicability and consistency. In multiple target search process, viewers will adopt exclusive and composite search strategies. The exclusive search strategy can be subdivided into the Z, W and O search patterns. The results show that when the number of targets is smaller than the number of distractors, the number of exclusive search strategy is significantly higher than that of composite search strategy. The exclusive search strategy spends less search time and fixation, which means it performs better in that situation.