輔助溝通（augmentative and alternative communication, AAC）系統提供暫時或長久失去語言溝通能力的族群，在符號、輔具、策略以及技術上的服務。其中，符號被視為AAC系統的基礎，然而相關研究多數在比較各系統符號的易用性，目前幾乎鮮少提出跨越系統、針對核心字彙符號的視覺設計概念方向以供未來系統符號設計參考。因此，本研究聚焦在符號本身的表徵透明度探討（transparency；係指能理解符號意義的程度，為符號易用性中評估具象性的方法），並以成人失語症患者為研究對象。研究符號為人的關係名詞、物體名詞、動詞和形容詞各別對應的核心字彙，並請專家進行符號的啟發式評估與樣本繪製，以AAC系統符號常見攝影和線條風格和動靜狀態來做探討。結果在第一階段的四個詞類符號靜態呈現研究上發現名詞類符號的表徵透明度最高，且研究對象認為攝影風格能呈現內容細節且生動令人愉悅的圖像是重要的；相對地，動詞和形容詞類符號的表徵透明度較低。第二階段的討論則專注在前階段表徵透明度較低的動詞和形容詞上，以攝影和線條兩種風格與動靜三種狀態來探討，試圖了解動態形式是否能提高動詞和形容詞符號的表徵透明度。經紮根分析結果發現，雖然動態形式能提高大部分動詞和形容詞符號的表徵透明度，但若形容詞本身較具抽象概念或其比較性的概念無法單純依賴具象表現時，則靜態呈現的效果較動態佳。整體而言在風格表現上，以攝影風格呈現名詞時，有較佳的表徵透明度與偏好結果；以線條風格呈現動作相關詞彙時，有較佳的表徵透明度與偏好結果。從狀態的結果來看，靜態適用表現抽象概念較多的字彙，靜態加輔助線適合表現有實際軌跡的動作；而動畫形式則能提高本身含有狀態、正向互動感受字彙符號的表徵透明度。

Augmentative and Alternative Communication (AAC) system could offer the service of symbol, aid, technology and strategy for people with temporary or permanent communication disabilities. In the AAC system, symbol has been regarded as the fundamental element. However, most related studies have focused on the comparisons of AAC symbols within systems and few have converted forward insights to common visual design principles for future core vocabulary symbol display. Meanwhile, limited literatures have recruited aphasia adult participants who are accounted for the largest proportion of communication disorder population. Therefore, the study was concentrated on the discussion of symbol transparency (the iconicity perspective of usability) with aphasia adults. At phase I, AAC symbols were classified as personal related noun, object noun, verb and adjective with opinions from researchers. Afterwards, HCI professionals with at least five years experiences, took heuristics evaluation and designed the symbols for each word-class with static photograph and illustrated based on current AAC symbol styles. The analysis showed that the noun symbols with photograph resulted in high transparency and preference while verb and adjective symbols resulted in low transparency. Based on the improving of the verb and adjective symbol transparency and preference, without static status, the two dynamic forms of static with supplement lines and animation were also studied (three levels in total) at phase II to investigation whether the dynamic characteristics could advance the symbol transparency and preference of verb and adjective. The findings demonstrated that dynamic forms could enhance most of the verb and adjective transparency and preference, but the adjectives with abstract concepts could not rely on visual cues and neither pure static forms. To sum up, photograph could improve the noun transparency/preference and illustration could raise action transparency/preference. Moreover, static status was applied to vocabularies contained large abstract concepts. The analysis showed that static status with supplement line form was relevant to action with visible movement traces while animation form could enhance the transparency in core vocabularies featuring more conditions and positive concepts.