呈現完整或部分圖文資訊對英語學習者影片理解之影響

Abstract

以影片等多媒體教材融入教學需要學習者對於畫面中的文字(verbal)和圖像(pictorial)資訊進行同步整合，然而由於大腦的認知資源有限，影片中的圖文呈現方式應考量學習者的認知負荷能力，以達到最有效的影片理解效果。因此，本研究旨在透過操控影片字幕(全字幕、部分字幕)和影像(動畫、關鍵畫面)的呈現模式，探討畫面中圖文資訊量的減少能否降低學習者的認知負荷並促進影片理解。共有62位台灣北部高職應外科的學生參與實驗，研究者參考受試者前兩學期的英語成就測驗表現，將受試者平均分配到四種影片模式：全字幕+動畫、全字幕+關鍵畫面、部分字幕+動畫、部分字幕+關鍵畫面。受試者在觀賞影片後即接受理解測驗，題目設計涵蓋三個層面(全面、局部、推論理解)，以期在整體理解分數下，進一步反映不同的理解深度。測驗結束後，研究者透過量表問卷調查受試者對其影片呈現模式的看法，及其在觀影過程中所感受的認知負荷類型(內在、外在、增生負荷)，為本研究提供相關的質性解釋和理論依據。研究結果顯示，雖然字幕呈現方式不影響各層面的影片理解，但圖像呈現方式對於影片的「整體理解」具有主要效果。其中，不論搭配全字幕或部分字幕，關鍵畫面皆能以適當的資訊量輔助學習者聚焦於文字處理並掌握影片重點；而受試者雖然較偏好動畫中豐富的視覺刺激，卻也表示這會導致他們無法同時注意及處理影片的字幕。另外，本研究也發現字幕和畫面的呈現方式對於影片的「局部理解」有顯著的交互作用，特別是在關鍵畫面下，搭配全字幕更能引導受試者從完整的文字敘述中汲取特定資訊；相反地，若是搭配部分字幕則會使資訊過於破碎，導致無法串連影片細節。本研究將圖像資訊的影響納入現存針對第二外語學習者的字幕研究，並證實影片中的圖文搭配會間接影響學習者的注意力和影片理解成效。據此，教師在透過影片實施教學時，可視教學目的或學生需要精進的理解層面來選擇或微調影片中的圖文呈現方式。Teaching and learning through video materials require the learner’s cognitive processing of concurrent verbal and pictorial information. To facilitate L2 learners’ video comprehension, the amount of presented information should thus be compatible with human’s finite cognitive capacity. In light of this, the current study aims to explore whether the reduction on verbal/pictorial information in a video yields lower cognitive load and better comprehension gain. The manipulation on caption mode and pictorial mode resulted in four viewing conditions (i.e., full captions + animation, full captions + static key frames, partial captions + animation, partial captions + static key frames). 62 participants were heterogeneously assigned to one of groups, and were instructed to complete the posttest measuring different aspects of comprehension (i.e., global, local, and inferential), as well as the questionnaire probing their perceived cognitive load (i.e., intrinsic, extraneous, and germane).The results showed that the pictorial mode of a video had significant effect on L2 learners’ overall comprehension. Specifically, while viewing the video presented in static key frames, the viewers were better able to focus on verbal processing with manageable amounts of visuals; this advantage was not as manifest when viewing the video displayed in the form of animation. The qualitative data further revealed that while the participants enjoyed the rich visual stimuli in animation, its dynamic feature was considered distracting for verbal processing, thus debilitating overall comprehension. Besides the significant effect on overall comprehension, static key frames were particularly beneficial for L2 learners’ local comprehension when presented with full captions. The current study highlights the potential impact of verbal and pictorial presentation modes on L2 video comprehension, which hopefully may serve as a useful guide for designing video materials for specific comprehension goals.