根據去個人化的社交認同模式，匿名性會導致團體中的成員，發生言論極化的情形。Facebook崛起後，在這種使用者資訊公開的社群媒體上，仍可以觀察到言論極化的現象。因此，本研究以感知匿名性，探討在PTT及Facebook兩種匿名性程度不同的社群媒體，所發生的言論極化現象。

研究結果發現，在感知匿名性不同的社群媒體上，皆會形成對社群的自我歸類，進而導致言論極化的現象。這個結果與SIDE的理論一致。而在感知匿名性低的網路環境，形成對社群的自我歸類的原因，是來自於人們外在自我覺察的提升。

According to Social identity model of deindividuation effects, anonymity will result in opinion polarization in the group. As Facebook proliferated, we can still find the polarization on this social media on which users have opened information. Based on perceived anonymity, the research tackles with polarization on two social media with different degrees of anonymity, PTT and Facebook.

The research found that users will develop self-categorization to on-line community which accordingly resulted in opinion polarization on social media with different degrees of anonymity. This consequence corresponds with SIDE. Besides, on the social media with low degree of anonymity, this research discovered that higher public self-awareness we have, much more will we develop self-categorization to on-line community.