漢語語篇中語義實體的篇章可及性

本文在向心理論的框架下，討論漢語語篇中語句所包含的語義實體（即後指中心集合成員）顯著度等級排序的依據。這一排序是預測某一語句中語義實體相對於其隨後語句的篇章可及性的依據。我們計算並分析了漢語含「把」、「給」、「放」、「被」四類句式的敘述性語篇片段中這四類語句與其之前和隨後語句間回指中心的過渡方式。通過具體的數據分析和比對，我們發現了以下模式和傾向：(1)話題位置的語義實體是維繫篇章連貫性的關鍵，所有觀察的語句均通過話題位置的語義實體實現與其之前和隨後語句間的回指中心延續；(2)除話題位置的語義實體外，後指中心集合成員的顯著度等級排序遵循題元角色序列等級，以題元序列為參考，越靠近左端的題元角色顯著度等級越高，越有機會被作為回指及優選中心；(3)話題的顯著度不受題元序列的影響，因此漢語後指中心集合成員的排序應分為兩個層級，第一層確認話題，第二層將剩餘語義實體按照題元序列排序，該排序決定語句中每一個語義實體的篇章顯著度和篇章可及性。

Adopting Centering Theory as its analytical tool, this article calculates the backward-looking center (Cb) transition states between ba/gei/fang/bei-utterance and the preceding utterance, as well as the subsequent utterance. The results show the following patterns: (1) Cb continuation is realized by the semantic entity in the topic position of all utterances; (2) the Thematic Hierarchy decides the prominence of the remaining semantic entities; (3) Since the prominence of the topic is not affected by the Thematic Hierarchy, a two-tier Cf-ranking is proposed. The first tier recognizes the topic as the most prominent semantic entity and ranks it the first in the Cf-ranking list; while the rest are ranked according to their positions in the Thematic Hierarchy. The Cf-ranking thus gained decides the discoursal prominence as well as the discoursal accessibility of all semantic entities in an utterance.