有些時候社會運動會循制度而行，有些時候則會透過集體行動挑戰體制。本研究將社會運動所採取的集體行動稱之為「抗爭事件」。透過抗爭事件，被排外者可由外而內地促成制度改變。 本研究的問題在於抗爭事件如何且在那些條件上，能夠造成改變。這邊指的條件分為四個層面：內部因素、外部因素、媒介效果與政治時機當透過抗爭事件能夠有效增進被排外者的權益，那抗爭應該被視為一種理性行為。同時，若抗爭能夠令制度改善，也該被看作是民主社會中一種必要的參與途徑。

Social movements either function within the institutional framework or they challenge the political system by collective actions. In this research, the collective actions in social movements are called "protest events". By protest events, the groups excluded from the political process aim at institutional changes from without. The question of this research is how and with what conditions the protest events could make changes. The conditions have four dimensions: internal factor, external factor, media effect and the strategic timing. When the rights of the excluded groups were improved with the protest events, the protest should be seen as a rational behavior. Besides, when protests lead to making the institutions better, it should be seen as necessary participation in the democratic system.