Document Type


Date of Award

Spring 5-31-2008

Degree Name

Doctor of Philosophy in Information Systems - (Ph.D.)


Information Systems

First Advisor

Starr Roxanne Hiltz

Second Advisor

Katia Passerini

Third Advisor

George Robert Widmeyer

Fourth Advisor

Naomi G. Rotter

Fifth Advisor

Marshall Scott Poole


Social networking sites have emerged as one of the most widely used types of interactive systems, with memberships numbering in the hundreds of millions around the globe. By providing tools for their members to manage an ever-changing set of relationships, social networking sites push a constant expansion of social boundaries. These sites place less emphasis on tools that limit social boundaries to enable privacy.

The rapid expansion of online social boundaries has caused privacy shockwaves. Privacy offline is enabled by constraints of time and space. Online, powerful search engines and long term digital storage means private data have no expiration date. Within an online culture of anonymity and fluid self-presentation of identity, social networking sites can be turned into places of perceived safety but with privacy risks that actually extend indefinitely.

While these sites do deploy privacy management features, it is not understood how people use social networking sites, how they use privacy management features, and how these two are related. In order to create better privacy mechanisms for social software, designers must first understand how members manage their privacy in the current environment.

This dissertation introduces The Social Software Performance Model, which describes relevant factors and their interaction in order to explain patterns of privacy management. The Model is a synthesis of Adaptive Structuration Theory, the Fit Appropriation Model and socio-technical systems theory. Adaptive Structuration Theory attempts to explain appropriation, defined as the process by which people integrate technology into their daily tasks and activities. A central premise of this research is that the appropriation perspective is a valuable lens for teasing apart how members of these sites adopt and adapt privacy management features.

Using Adaptive Structuration Theory, this dissertation developed and validated new measures that capture appropriation patterns related to privacy management within social networking sites. The research introduces three independent constructs that measure privacy management appropriation. They are the Use appropriation move, which measures actual use of privacy management features; the Familiarity appropriation move, which measure knowledge of privacy management features; and the Restricted Scope appropriation move, which measures the extent to which members independently limit the scope of their online social network to protect their privacy.

Survey data was collected from subjects in two different social networking sites, Facebook and MySpace, and used to evaluate hypotheses developed from The Social Software Performance Model. Using a partial least squares analysis, the research model explained 28.5% of the variance with respect to appropriation of privacy management features. This is a strong result for exploratory research.

This research makes a contribution by extending theories to a new context, by applying both the Adaptive Structuration Theory and the Fit Appropriation Model to the use of privacy management in social networking sites. Using types and sub-types of appropriation moves from Adaptive Structuration Theory, new measures were developed and validated. These new measures, with further efforts to establish validity and reliability, can be adapted to understand appropriations for other forms of social software.

The main finding of the research is a method to evaluate the effectiveness of different implementations of privacy management within social networking sites. While information system theory has been primarily concerned with systems used in an organizational context, the results of this research shows these theories are relevant to new systems based on social interaction.

These new types of social software, generically labeled as Web 2.0, are among the most popular on the Internet. Besides Facebook and MySpace, examples of Web 2.0 include the video sharing site, and the photo sharing site These sites thrive on intensive social interaction, and are growing in scope and importance. There has been little consensus among researchers as to how to measure the effectiveness of Web 2.0 systems. This lack of consensus presents a strategic opportunity for information systems theory, which has made determinations of effectiveness an important focus. This research has adapted information systems theory to study the effectiveness of privacy management.

The development of privacy management has proven to be a difficult problem, and a deeper understanding of its effectiveness is expected to improve the overall design of these systems. By adapting information systems theory to the use of privacy management within social networking sites, this research shows that information systems theory can also be used applied to Web 2.0 applications. This provides a foundation for the further development of methods to measure the effectiveness of additional components within social software.



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