以眼動型態和閱讀測驗表現探討箭頭在科學圖文閱讀中的圖示效果

The Effect of Arrows in an Illustration When Reading Scientific Text: Evidence from Eye Movements and Reading Tests

前人的研究顯示箭頭在讀圖理解上扮演重要角色。從功能性的角度來看，箭頭提供部件之間的方向關係與序列訊息，使得讀者能形成較佳的圖像表徵，對閱讀產生助益；相反的，在圖上呈現多個箭頭也可能使得知覺複雜性太高，以致於分散讀者的注意力而得到反效果。本研究藉由眼球追蹤技術記錄大學生閱讀圖文並置的科學文章，探討箭頭對讀者在科學圖文整合認知歷程的影響，並以閱讀測驗檢視箭頭的圖示效益。實驗操弄圖示箭頭的有無，兩種版本的圖都搭配相同的文章。受試者被隨機分派去讀其中一種版本，讀完文章後須回答閱讀測驗題。研究結果顯示：一、在測驗題的表現上，有箭頭組在序列題與統整題的答題正確率都高於無箭頭組；二、在眼動資料的分析上，有箭頭組僅在圖上的平均跳視距離較無箭頭組短，其餘包括總凝視時間、圖凝視時間、圖佔總凝視時間比、圖文之間移動次數均無差異；三、兩組在三種閱讀軌跡的比率差異僅邊緣顯著。本研究的閱讀測驗結果雖然支持箭頭的正向功能，但眼動指標上並無一致的效果，本文透過與文獻的比較，以閱讀材料特性與測驗性質來討論兩類結果不一致的可能意義。文末討論眼動指標即使未顯現兩組的差異，仍提供了圖文閱讀歷程的訊息及指出未來可能的研究方向。

Previous researches have shown that the use of arrows can aid the comprehension of graphical information. From the functional perspective, arrows can provide useful information about sequential relations between graphical components and indicate pathway directions. However, the presence of excessive arrows in an illustration may produce negative effects related to perceptual complexity and division of attention. In this study we investigated the effect of using arrows in an illustration when reading scientific text by recording viewers' eye movements and obtaining their reading test scores. The participants first read a scientific text that included an illustration either with or without arrows (arrow group versus nonarrow group), and then they completed a reading test. The accuracy on the “sequential items” and “integrative items” was higher and the mean saccade length on an illustration was shorter for the arrow group than for the nonarrow group, but there were no differences between the groups in total fixation duration, fixation duration on an illustration, the ratio of the total fixation duration on an illustration, and the number of saccades between text and an illustration. Although the results of the reading test supported that arrows have a positive effect on the reading of illustrations, the results for eye movements were inconsistent. Alternative explanations are discussed based on comparing the types of materials and reading tests between our and previous studies. The indicators of eye movements that reflect possible processes involved when reading illustrations and text are also discussed.