Computers play an increasingly large part in childrens daily lives, yet most interface design research has focused on adult users. One area of research that has informed adult interface design is the Media Equation, which explains how people respond to media in a fundamentally social manner and how they treat computers as social actors in interactions. To date, it was unknown whether these findings apply to children as well. This thesis investigates the effects of the Media Equation on children in three specific areas: praise, team formation, and politeness. It also examines whether varying the form of the computer affects the Media Equation in any way and whether there are any gender differences in how children respond to the Media Equation. <p> Little evidence was found to support the existence of Media Equation effects on children. Children responded positively regardless of whether any Media Equation elements were incorporated into the interfaces. These results raise doubts on whether there is any added value to including Media Equation principles into the design of childrens interfaces. The results do, however, shed some light on children-computer interaction and lead to a set of guidelines for designers of childrens technology.

Direct interaction in virtual environments can be realized using relatively simple hardware, such as standard webcams and monitors. The result is a large gap between the stimuli existing in real-world interactions and those provided in the virtual environment. This leads to reduced efficiency and effectiveness when performing tasks. Conceivably these missing stimuli might be supplied through a visual modality, using sensory substitution. This work suggests a display technique that attempts to usefully and non-detrimentally employ sensory substitution to display proximity, tactile, and force information. We solve three problems with existing feedback mechanisms. Attempting to add information to existing visuals, we need to balance: not occluding the existing visual output; not causing the user to look away from the existing visual output, or otherwise distracting the user; and displaying as much new information as possible. We assume the user interacts with a virtual environment consisting of a manually controlled probe and a set of surfaces. Our solution is a pseudo-shadow: a shadow-like projection of the user's probe onto the surface being explored or manipulated. Instead of drawing the probe, we only draw the pseudo-shadow, and use it as a canvas on which to add other information. Static information is displayed by varying the parameters of a procedural texture rendered in the pseudo-shadow. The probe velocity and probe-surface distance modify this texture to convey dynamic information. Much of the computation occurs on the GPU, so the pseudo-shadow renders quickly enough for real-time interaction. As a result, this work contains three contributions: a simple collision detection and handling mechanism that can generalize to distance-based force fields; a way to display content during probe-surface interaction that reduces occlusion and spatial distraction; and a way to visually convey small-scale tactile texture.

Machine-readable privacy policies have been developed to help reduce user effort in understanding how websites will use personally identifiable information (PII). The goal of these policies is to enable the user to make informed decisions about the disclosure of personal information in web-based transactions. However, these privacy policies are complex, requiring that a user agent evaluate conformance between the users privacy preferences and the sites privacy policy, and indicate this conformance information to the user. The problem addressed in this thesis is that even with machine-readable policies and current user agents, it is still difficult for users to determine the cause and origin of a conflict between privacy preferences and privacy policies. The problem arises partly because current standards operate at the page level: they do not allow a fine-grained treatment of conformance down to the level of a specific field in a web form. In this thesis the Platform for Privacy Preferences (P3P) is extended to enable field-level comparisons, field-specific conformance displays, and faster access to additional field-specific conformance information. An evaluation of a prototype agent based on these extensions showed that they allow users to more easily understand how the website privacy policy relates to the users privacy preferences, and where conformance conflicts occur.

A recent survey of studies related to digital libraries concluded that students use and like electronic resources. However, the results of access studies show that actual use of online content is relatively low, with only 10-20% of students making regular use of the content. This is because navigation to the online content in these collections is not convenient, requires multiple steps in order to reach relevant content, and is not integrated into a students natural workflow. In our research, we have designed, deployed, and evaluated a method for making content available to students that targets the content to their current need and is designed as an alternative yet cooperative method of access to a well-structured set of course content. Since notes are both integral to lecture classes and generally ubiquitous, it is a natural target for connecting the student with available content. Pen technologies and mobile devices make it possible for us to capture student notes and enhance them with embedded access links to relevant content. In our initial interface, NoteNexus, instead of delivering content as the result of a student search query or browsing activity, we embedded links to the content into the students notes. NoteNexus did not produce a change in the student use of online content. C-Nexus was designed and developed from the results of the NoteNexus study. C-Nexus was successful in increasing the student use of online content.

People must frequently sort through and identify relevant materials from a large set of documents. Document triage is a specific form of information collecting where people quickly evaluate a large set of documents from the Internet by reading (or skimming) documents and organizing them into a personal information collection. During triage people can re-read documents, progressively refine their organization, and share results with others. People usually perform triage using multiple applications in concert: a search engine interface presents lists of potentially relevant documents; a document reader displays their content; and a text editor or a more specialized application records notes and assessments. However, people often become disoriented while switching between these subtasks in document triage. This can hinder the interaction between the subtasks and can distract people from focusing on documents of interest. To support document triage, we have developed an environment that infers users’ interests based on their interactions with multiple applications and on an analysis of the characteristics and content of the documents they are interacting with. The inferred user interest is used to relieve disorientation by generating visualizations in multiple applications that help people find documents of interest as well as interesting sections within documents.

Thesis (Ph.D.)--Drexel University, 2009. / Includes abstract and vita. Includes bibliographical references (leaves 207-216).

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 95-104).

Thesis (M.S.)--University of Pennsylvania, 1981. / "August 1981." Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 308-332).

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 86-95). Also available on the Internet.