Master of Science / Department of Computing and Information Sciences / Xinming Ou / Attack graphs present a visual representation of all the potential vulnerabilities and attack paths in a network. They act as a vital security tool in finding the critical attack paths in the enterprise wide networks. Generated attack graphs for complex networks present thousands of attack paths to visualize and represent to the end user. Enhancing the visualization of attack graphs by adding user interactivity will greatly improve in analyzing attack graphs and identifying the critical attack paths in the enterprise network. The layout of the attack graph can be adjusted to represent the layout of the real world enterprise network. Adding user interactivity to attack graphs is done using Prefuse, a software framework written in Java for information visualization. Prefuse is flexible and got the ability to render large amounts of data in an efficient manner. The visualization framework for the attack graphs provides a GUI tool for interacting with attack graph. The framework is a layered architecture with two important layers, the static layer and the dynamic layer. The static layer translates the attack graph trace generated from MuLVAL into a standard graphviz dot language descriptive file. The dynamic layer translates the graphviz dot file into a graph object that can be interpreted and visualized using the prefuse software framework. Preliminary result in this work has been published in [19].

Doctor of Philosophy / Department of Mathematics / Andrew G. Bennett / The goal of this work is to provide instructors with detailed information about their classes at each assignment during the term. The information is both on an individual level and at the aggregate level. We used the large number of grades, which are available online these days, along with data-mining techniques to build our models. This enabled us to profile each student so that we might individualize our approach. From these profiles, we began to investigate what can be done in order to get students to do better, or at least be less frustrated. Regardless, the interactions with our undergraduates will improve as our knowledge about them increases. We start with a categorization of Studio College Algebra students into groups, or clusters, at some point in time during the semester. In our case, we used the grouping just after the first exam, as described by Dr. Rachel Manspeaker in her PhD. dissertation. From this we built a naive Bayesian model which extends these student clusters from one point in the semester, to a classification at every assignment, attendance score, and exam in the course. A hidden Markov model was then constructed with the transition probabilities being derived from the Bayesian model. With this HMM, we were able to compute the most likely path that students take through the various categories over the semester. We observed that a majority of students settle into a group within the first two weeks of the term.

Public library services are evolving in response to the changing informational needs and behaviours of the citizens of the knowledge society. Reference statistics are declining and the move to self-service, virtual reference and an increasing use of mediating information and communication technologies calls into question the ongoing role of human, face-to-face information interaction at the public library’s front-line reference “desk”. An ethnographic case study of face-to-face adult reference service was conducted in a large Canadian urban public library. Over 8 months during 2006, a pilot study was conducted, followed by 170 hours of observations at the reference desks in three branch libraries of varying sizes and semi-structured interviews with front-line reference staff, library managers and reference service clients. 480 reference interactions were documented and policy documents were reviewed. An inductive staged process of analytical abstraction, a narrative approach to the interpretations and a critical reflexivity as participant researcher were employed. The main contribution of this study is the articulation of a practice framework for understanding and studying the reference service within the public library as organization. Sharing knowledge, finding meaning and learning are the outcomes of this epistemic practice. A typology of four reference encounters characterized in three dimensions of interpersonal communication; information exchange and mode of practice is detailed. This study challenges previous interpretations of reference services as a transactional, unitized question-answer activity and depicts it in a larger context as an interactional, relational set of activities that altogether characterize an epistemic practice. The three dimensions of structure (library organization), agency (reference staff and clients) and objects (library collections) anchor this conceptual framework – they are interdependent dimensions interacting to illuminate a robust understanding of face-to-face reference service. This study responds to previous research in which the reference process is studied separately from its social practice and its structural-organizational contexts.

While there are exemplary studies on the relationships between social networks and media such as television and the Internet, less is known about the social network consequences of mobile phone use during life-stage transitions. This study investigates the roles that mobile phones play in supporting the relationships of young people as they transition to and through their first-year of university in Toronto, Canada. Focussing on information practices during a transition that tests the resilience of support networks, this study queried the extent to which mobile phones play a role in keeping relationships intact, enabling students to maintain a sense of social cohesion and belonging. Data were collected from November 2007 to September 2008 through a longitudinal research design. Socio-technical concepts and network analysis techniques were applied to analyze the ways in which mobile communication is embedded in the everyday social life of young people aged 17-34. Set within the culturally-specific context of urban Canada, the data provided substantial evidence that mobile phones foster social cohesion within intimate relations but provide a more tenuous platform from which to nurture new relationships. First-year undergraduates have integrated the mobile phone into the way they engage with their social networks to a considerable degree, with commuter students experiencing additional tensions in negotiating relationships from home and on-campus. Findings showed that mobile phones were the devices of choice to mitigate feelings of loneliness, with deleterious consequences for the development of new relationships. Furthermore, the mobile phone was a key contributor to a rising sense of empowerment and autonomy for young adults as they negotiated identity transformations during their rite of passage into adulthood. Issues of trust and reciprocity in forming new relationships were mediated through a continuum of social media of which the mobile phone was the most intimate. Evidence of continuous access to social networks has broader implications for how mechanisms for coping with being alone and disconnection are acquired in this generation. Finally, observations of ritualistic interaction practices involving mobile phones may be theorized as small-scale evidence of larger societal shifts from collective constructs of community to that of networked individuals.

While linguistic skill is a hallmark of humanity, the increasing volume of linguistic data each of us faces is causing individual and societal problems — ‘information overload’ is a commonly discussed condition. Tasks such as finding the most appropriate information online, understanding the contents of a personal email repository, and translating documents from another language are now commonplace. These tasks need not cause stress and feelings of overload: the human intellectual capacity is not the problem. Rather, the computational interfaces to linguistic data are problematic — there exists a Linguistic Visualization Divide in the current state-of-the-art. Through five design studies, this dissertation combines sophisticated natural language processing algorithms with information visualization techniques grounded in evidence of human visuospatial capabilities. The first design study, Uncertainty Lattices, augments real-time computermediated communication, such as cross-language instant messaging chat and automatic speech recognition. By providing explicit indications of algorithmic confidence, the visualization enables informed decisions about the quality of computational outputs. Two design studies explore the space of content analysis. DocuBurst is an interactive visualization of document content, which spatially organizes words using an expert-created ontology. Broadening from single documents to document collections, Parallel Tag Clouds combine keyword extraction and coordinated visualizations to provide comparative overviews across subsets of a faceted text corpus. Finally, two studies address visualization for natural language processing research. The Bubble Sets visualization draws secondary set relations around arbitrary collections of items, such as a linguistic parse tree. From this design study we propose a theory of spatial rights to consider when assigning visual encodings to data. Expanding considerations of spatial rights, we present a formalism to organize the variety of approaches to coordinated and linked visualization, and introduce VisLink, a new method to relate and explore multiple 2d visualizations in 3d space. Intervisualization connections allow for cross-visualization queries and support high level comparison between visualizations. From the design studies we distill challenges common to visualizing language data, including maintaining legibility, supporting detailed reading, addressing data scale challenges, and managing problems arising from semantic ambiguity.

This doctoral study investigates the nature and role of leisure reading in the lives of avid immigrant readers. Guided by hermeneutic phenomenology and conducted by means of surveys and in-depth interviews, it uses a sample of Russian-speaking immigrants in Toronto, Canada, as a case study. The overarching research problem is divided into three research questions (RQ): RQ1: Who are the readers? RQ2: What are the main characteristics of reading behavior and habits of participants after immigration? RQ3: What role does leisure reading play in participants’ lives in immigration? Answering RQ1, the study paints demographic and socio-cultural portraits of participants; recreates a variety of contexts shaping their reading; and unfolds their reader histories. In response to RQ2, it traces immediate post-immigration fluctuations in reading behavior; records the most peculiar reading contents; explores participants’ self-perceptions as readers; outlines the major areas of post-immigration changes in leisure reading; and presents the analysis of acculturation stress in the area of leisure reading. It is concluded that leisure reading can be a more sensitive indicator of acculturation than more utilitarian measures, because it can open a window to the cultural and psychological intricacies of acculturation. Finally, RQ3 generates a theoretical discussion of the concept of ‘the role of reading’ and determines the study focus on immigration-specific, emotional and instrumental, roles. Leisure reading is found important in coping with the culture shock; sharing the experience of others and assessing personal immigration paths; re-evaluating the history of the fatherland and gaining a new perspective on the national heritage; stabilizing identity; learning about the new country; improving English-language proficiency; and compensating for the deficiencies of a transitional period. In addition, leisure reading emerges as a powerful force cementing ethnic and transnational reading communities. The study expands the selected acculturation models and theories; introduces clarity to the concepts of the role and appeal of reading; highlights the dual and self-reinforcing function of reading as a measure and a determinant of acculturation. Finally, it presents a systematic examination of the ethnic readership that has escaped the attention of reading researchers in the largest immigrant-receiving countries, Canada and the United States.

While credibility perception on the Web is a well-researched topic across multiple disciplines, extant studies have not considered nonvisual modalities of Web access. This research explores how Web users who are blind or visually impaired perceive the credibility of online information and how the screen reader used by them to interact with the Web mediates the process. Credibility perception was studied in the context of the screen reader users’ everyday information practices, examining in depth the effect of Web accessibility on their online information interactions, information practices and credibility perception. Adopting an exploratory approach, a sequential multimethods research design was used. Between April and July 2008 data were collected from adult screen reader users residing in Ontario, Canada through an electronic questionnaire survey (N=60) to identify salient issues, which were then examined deeper through semi-structured interviews with a subsample (N=13) during June 2009. Hands-on online information activities (with participant observation and think-aloud protocol) were also conducted during the interview session. Primary findings emerged through qualitative content analysis of descriptive data, with quantitative results guiding and supplementing the analysis. Online information credibility perception is found to be a dynamic and social process. It is governed by users’ assumptions based on their past experiences, personal knowledge/beliefs and social inputs. Assumptions evolve over time and usage into personal heuristics. The credibility perception process spans three phases—prediction, evaluation and corroboration—permeating the information seeking, using and sharing practices of users. Evaluation of website and web content depends on users’ online interaction proficiency and is bounded by the interface affordances provided by the screen reader and the amount of meta-information provided by the websites for interpreting visual/spatial features. Community support scaffolds users towards more effective technology management and credibility perception. Therefore, promoting inclusion in the online participatory culture will enhance the information practices of screen reader users.

This thesis investigates the policy frames employed by civil society organizations (CSOs) in the network neutrality debate in Canada and the United States. Network neutrality is defined as restrictions on Internet Service Providers (ISPs) to respect freedom of expression on the Internet and not seek to prevent innovative competition nor control the services or content available to users. The primary question under investigation is the policy frames of CSOs in the debate. The second question is whether CSOs have influenced policy outcomes in either legislation or regulation. The focus of the analysis is on regulatory agencies (CRTC and FCC); proposed legislation in Parliament and Congress is also analyzed as well. By examining the arguments advanced by various policy participants (government, ISPs, and CSOs), common points can be identified that may help the participants come to agreement.

Many Library and Information Science (LIS) scholars have long articulated the importance of physical and social settings—the environment—when examining how individuals acquire, store, organize, maintain, dispose of, and use information in one of their home or work lives. Yet, few have raised the question of how these information practices are altered and affected in home office spaces, fused living and working environments that lie at the intersection of the personal and the professional. This thesis resulted from an exploratory, ethnographic research study centred upon describing and analyzing the habits of information management and information use that characterize home office settings—specifically, professional home offices that each serve as their user’s only workplace. It argues that the professional home office differs from both traditional professional offices in corporate or institutional settings and from personal home offices used for non-professional tasks and pursuits. The professional home offices of four printing company account managers provided the field from which data was gathered, collected by way of guided tours, diagramming, photography, interviews, and observation. Findings suggest that information practices in professional home offices are a continual negotiation between the two spheres of household and organization, but that this will not necessarily imply a compromise of one for the other.

Radio frequency identification (RFID) is a technology used in many applications for the identification of objects. This thesis presents a concept of how libraries could use RFID technology to locate physical items within the library. The ability to locate items within the library changes the way users interact with physical material, creates new ways of user collaboration, and influences the ability to browse the shelves for physical items. Several implementation scenarios are presented in detail and implications on collaboration and browsing are analyzed.