Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Computer Science

First Advisor

Dr. Gert-Jan de Vreede

Second Advisor

Dr. Lotfollah Najjar

Third Advisor

Dr. Matt Germonprez

Fourth Advisor

Dr. Jeremy Harris Lipschultz


In extreme events such as the Egyptian 2011 uprising, online social media technology enables many people from heterogeneous backgrounds to interact in response to the crisis. This form of collectivity (an online crowd) is usually formed spontaneously with minimum constraints concerning the relationships among the members. Theories of collective behavior suggest that the patterns of behavior in a crowd are not just a set of random acts. Instead they evolve toward a normative stage. Because of the uncertainty of the situations people are more likely to search for norms.

Understanding the process of norm formation in online social media is beneficial for any organization that seeks to establish a norm or understand how existing norms emerged. In this study, I propose a longitudinal data-driven approach to investigate the dynamics of norm formation in online crowds. In the research model, the formation of recurrent behaviors (behavior regularities) is recognized as the first step toward norm formation; and the focus of this study is on the first step. The dataset is the tweets posted during the Egyptian 2011 movement. The results show that the social structure has impact on the formation of behavioral regularities, which is the first step of norm formation. Also, the results suggest that accounting for different roles in the crowd will uncover a more detailed view of norm and help to define emergent norm from a new perspective. The outcome indicates that there are significant differences in behavioral regularities between different roles formed over time. For instance, the users of the same role tend to practice more reciprocity inside their role group rather than outside of their role.

I contribute to theory first by extending the implications of current relevant theories to the context of online social media, and second by investigating theoretical implications through an analysis of empirical real-life data. In this dissertation, I review prior studies and provide the theoretical foundation for my research. Then I discuss the research method and the preliminary results from the pilot studies. I present the results from the analysis and provide a discussion and conclusion.


A DISSERTATION Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Doctor of Philosophy. Copyright 2016 Nargess Tahmasbi.

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