本研究以台灣2004年「319槍擊事件」發生後許多網路使用者從網路上收到「槍擊疑雲電子郵件」的時空背景，檢測「第三人效果」與「第一人效果」是否存在，並進一步探討第三人效果的行為效應。本文測試的行為效果有二，一為「支持規範」，二為「轉寄電子郵件」。「網路問卷調查法」是本研究採行的研究方法，研究結果顯示，對所有接觸過319「槍擊疑雲」電子郵件的受訪者而言，第三人效果的確存在，而泛綠支持者的第三人效果較泛藍支持者與中立者更為強烈，但第一人效果卻未如期發生在泛藍支持者身上。另外，第三人效果對於「支持規範」的預測力未達顯著，但對「電子郵件之轉寄」則有顯著影響力。

This study aims to examine the third-person effect and the first-person effect. Fit also explores the behavioral aspects of the third-person effect. The behavioral outcomes in this study are people’s desire for regulation and their behavior towards “email-transmission.” An online survey was applied in this study. The questionnaire was posted on the web for a span of three weeks after the 2004 Taiwan Presidential Election when 319-assassination-related emails roamed the Internet. The results show that the third-person effect does emerge. The users who support the Pan-Green party are more likely than Pan-Blue supporters and Independents to perceive that their emails exert a stronger influence on others than on themselves. However, the Pan-Blue supporters do not perceive themselves to be more affected than others. In addition, the third-person effect is not a significant predictor of perceived need for regulation. However, it does play a role in predicting the “email-transmission.”