哈貝馬斯的公共領域理論是研究大眾媒體再現民意的主導範式，但在目前的討論中，媒介報道中的消息來源是反映民意的主要指標，批判的層面多集中于媒體本身的政治立場和商業利益。本研究以太陽花學運期間台灣四大主流報紙的讀者投書為研究對象，採取內容分析的方式，以溝通理性的視角來解釋媒體與公共領域的關係，從“多元”和“互動”兩個維度來檢視大眾媒體在學運期間再現民意的傳播表現。研究發現：各報讀者投書所呈現出的社運角色以單一的第三者為主，第三者中又以專家學者為主，忽略對於處理者（政府）和行動者（學生）的呈現；就呈現的論述議題而言，各報集中呈現“學運過程”、“學運中公權力的作為”與“學運背後的台灣民主”三項議題，忽略對於服貿主題及“學運中青年世代”等其他深層次議題的呈現；態度類型中，各報雖均有自己的立場，但總體而言，“支持學運”的態度占主導位置，最後在情感結構的呈現上，除《中國時報》較為偏重情感性表達外，各報的認知性表述與情感性表達相當，在情感表達中，以強硬-憤怒為主的負面情緒抑制了其他情感的呈現。四大報在以上四個類目中多元性的缺位擠壓和扭曲了參與者在此一公共空間中對話和互動的品質。在互動性的層面，《聯合報》基本形成了處理者、行動者和第三者之間基於不同態度的互動，其餘三報在角色呈現和態度表達上均不同程度地存在“一言堂”的現象，互動品質較低。總體來看，四報基於特定主題的意見再現均已第三者為主，均已負面情緒為主。

Habermas’ Public Sphere theory is the dominant paradigm of the study of mass media representing public opinion. However, in the present discussion, public opinion is mainly replaced by sources of the stories, and the critiques focus on the political stance and commercial interests of the media. Taking the readers letters to the four mainstream newspapers in Taiwan during the Sunflower Movement as the research object, this article employs content analysis and Communicative Rationality to explain the relationship between the media and the public sphere, and examine the performance of the mass media during the movement from the dimensions of pluralism and interaction. It turns out that readers letters to the four newspapers are mainly written by a single role of social movement as spectators, of which specialists and scholars is the dominant part, thus ignoring the representation of the dealers (government) and the actors (students). As to the issues discussed, the newspapers focus on three issues, which is the movement process, the government’s behavior during the movement, and Taiwan's democracy behind the movement, and ignore those deeper topics such as CSSTA and the youth generation in Taiwan. In terms of the attitudes, despite the four newspapers having their own position, the attitude of supporting the movement is the majority. Finally, in the respect of representing feeling structure, in addition to the China Times ’ preference for emotional expression, the other newspapers show equal proportion of cognitive and emotional expression. And in the emotional expression, negative emotion, mostly tough-anger, suppresses other emotions. Moreover, the absence of pluralism squeezes and twists the quality of the participants ’ dialogue and interaction in this public space.In the dimension of interaction, United Daily News basically forms an interaction between dealers, actors and spectators despite of their different attitudes. The other three share different degrees of monologue, leading to low quality of interaction. In general, all four newspapers ’ representation of the public opinion is dominantly composed of spectators ’ comments and negative emotions.