Refinding electronic information is a common problem, yet it has received less study than the problem of how to find information for the first time. In this dissertation, I examine how people approach tasks to refind information they have seen on the Web and factors that may affect refinding. I conducted a controlled, laboratory study in which participants participated in two sessions: one to find information for a set of 18 tasks and a second session, about a week later, to attempt a set of counterpart refinding tasks. Results indicate that finding and refinding do have differences, but not for all types of tasks. The use of Web search engines was not observed to change significantly from the first session to the second. However, for tasks that participants were more familiar with, search engines were used less. Tasks that involved refinding a subset of the information that was found in the first session took longer to complete and were perceived as more difficult. Participants often went directly to known resources on the Web to start their searches. These sets of known resources included many on-line counterparts of paper resources such as telephone directories, dictionaries, and newspapers. For many tasks, participants used the same starting strategy to refind the information that they used find it, indicating strong patterns of access. This work contributes to the base of knowledge about how people refind information and the factors that affect refinding. It also contributes to the research field of information refinding and personal information management by identifying dimensions and factors that affect refinding. The results reported have implications for the design of Web sites and information repositories, the design of tools to help users find and refind information, and for the research community studying personal information management. / Ph. D.

Multiple devices such as desktops, laptops, and cell phones are often used to manage users' personal information, such as files, calendars, contacts, emails, and bookmarks. This dissertation presents the results of two studies that examined users' mental workload in this context, especially when transitioning tasks from one device to another. In a survey of 220 knowledge workers, users reported high frustration with current devices' support for task migration, e.g. making files available on multiple machines. To investigate further, I conducted a controlled experiment with 18 participants. While they performed PIM tasks, I measured their mental workload using subjective measures and physiological measures. Some systems provide support for transitioning users' work between devices, or for using multiple devices together; I explored the impact of such support on mental workload and task performance. Participants performed three tasks (Files, Calendar, Contacts) with two treatment conditions each (lower and higher support for migrating tasks between devices.) This dissertation discusses my findings: workload measures obtained using the subjective NASA TLX scale were able to discriminate between tasks, but not between the two conditions in each task. Task-Evoked Pupillary Response, a continuous measure, was sensitive to changes within each task. For the Files task, a significant increase in workload was noted in the steps before and after task migration. Participants entered events faster into paper calendars than into an electronic calendar, though there was no observable difference in workload. For the Contacts task, task performance was equal, but mental workload was higher when no synchronization support was available between their cell phone and their laptop. Little to no correlation was observed between task performance and both workload measures, except in isolated instances. This suggests that neither task performance metrics nor workload assessments alone offer a complete picture of device usability in multi-device personal information ecosystems. Traditional usability metrics that focus on efficiency and effectiveness are necessary, but not sufficient, to evaluate such designs. Given participants' varying subjective perceptions of these systems and differences in task-evoked pupillary response, aspects of hot cognition such as emotion, pleasure, and likability show promise as important parameters in system evaluation. / Ph. D.

Thesis (Ph. D.)--University of Oregon, 2001. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 232-236). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 218-227). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (p. 169-179).

Thesis (Ph. D.)--University of Rhode Island, 2003. / Typescript. Includes bibliographical references (leaves 159-169).

Thesis (M.S.)--Rochester Institute of Technology, 2006. / Typescript. Includes bibliographical references (leaves 64-71).

The increasing number of devices owned by a single user makes it increasingly difficult to access, organise and visualise personal information (PI), i.e. documents and media, across these devices. The primary method that is currently used to organise and visualise PI is the hierarchical folder structure, which is a familiar and widely used means to manage PI. However, this hierarchy does not effectively support personal information management (PIM) across multiple devices. Current solutions, such as the Personal Information Dashboard and Stuff I’ve Seen, do not support PIM across multiple devices. Alternative PIM tools, such as Dropbox and TeamViewer, attempt to provide a means of accessing PI across multiple devices, but these solutions also suffer from several limitations. The aim of this research was to investigate to what extent enhanced information visualisation (IV) techniques could be used to support accessing PI across multiple devices. An interview study was conducted to identify how PI is currently managed across multiple devices. This interview study further motivated the need for a tool to support visualising PI across multiple devices and identified requirements for such an IV tool. Several suitable IV techniques were selected and enhanced to support PIM across multiple devices. These techniques comprised an Overview using a nested circles layout, a Tag Cloud and a Partition Layout, which used a novel set-based technique. A prototype, called MyPSI, was designed and implemented incorporating these enhanced IV techniques. The requirements and design of the MyPSI prototype were validated using a conceptual walkthrough. The design of the MyPSI prototype was initially implemented for a desktop or laptop device with mouse-based interaction. A sample personal space of information (PSI) was used to evaluate the prototype in a controlled user study. The user study was used to identify any usability problems with the MyPSI prototype. The results were highly positive and the participants agreed that such a tool could be useful in future. No major problems were identified with the prototype. The MyPSI prototype was then implemented on a mobile device, specifically an Android tablet device, using a similar design, but supporting touch-based interaction. Users were allowed to upload their own PSI using Dropbox, which was visualised by the MyPSI prototype. A field study was conducted following the Multi-dimensional In-depth Long-term Case Studies approach specifically designed for IV evaluation. The field study was conducted over a two-week period, evaluating both the desktop and mobile versions of the MyPSI prototype. Both versions received positive results, but the desktop version was slightly preferred over the mobile version, mainly due to familiarity and problems experienced with the mobile implementation. Design recommendations were derived to inform future designs of IV tools to support accessing PI across multiple devices. This research has shown that IV techniques can be enhanced to effectively support accessing PI across multiple devices. Future work will involve customising the MyPSI prototype for mobile phones and supporting additional platforms.

The web browser has emerged as a central workspace for information workers, where they make use of cloud-based applications to access their information. While this solution nicely supports access to their data from multiple devices, it presents a nightmare for organizing and coordinating data between tools for a single project. Information is typically scattered between various online tools, where storage and organization structures are replicated. Information workers are interrupted and have to switch between projects frequently. Once interrupted, resuming work on a project can be hard. To address this information fragmentation and the impact of work interruptions, I created Contextinator, a personal information manager for the web browser that lets information workers organize their work activity and information into projects. Contextinator assists in coordinating information for projects, thereby ameliorating information fragmentation for projects that live on the cloud. It assists information workers in context switching and resuming work after interruptions. In my the- sis, I describe the problem of information fragmentation in the cloud. I discuss the different areas of related work of Personal Information Management, the design of Contextinator and how it is grounded in previous research. I briefly discuss how Contextinator is implemented. I then present the results from my field-evaluation of Contextinator. Finally, I conclude by discussing future work in this research. / Master of Science

Die Verwaltung persönlicher, multimedialer Dokumente kann mit Hilfe semantischer Technologien und Ontologien intelligent und effektiv unterstützt werden. Dies setzt jedoch Verfahren voraus, die den grundlegenden Annotations- und Bearbeitungsaufwand für den Anwender minimieren und dabei eine ausreichende Datenqualität und -konsistenz sicherstellen. Im Rahmen der Dissertation wurden notwendige Mechanismen zur semi-automatischen Modellierung und Wartung semantischer Dokumentenbeschreibungen spezifiziert. Diese bildeten die Grundlage für den Entwurf einer komponentenbasierten, anwendungsunabhängigen Architektur als Basis für die Entwicklung innovativer, semantikbasierter Lösungen zur persönlichen Dokumenten- und Wissensverwaltung. / Personal multimedia document management benefits from Semantic Web technologies and the application of ontologies. However, an ontology-based document management system has to meet a number of challenges regarding flexibility, soundness, and controllability of the semantic data model. The first part of the dissertation proposes necessary mechanisms for the semi-automatic modeling and maintenance of semantic document descriptions. The second part introduces a component-based, application-independent architecture which forms the basis for the development of innovative, semantic-driven solutions for personal document and information management.