The Mole: a pressure-sensitive mouse

The traditional mouse enables the positioning of a cursor in a 2D plane, as well as the interaction of binary elements within that plane (e.g., buttons, links, icons). While this basic functionality is sufficient for interacting with every modern computing environment, it makes little use of the human hand\u27s ability to perform complex multi-directional movements. Devices developed to capture these multi-directional capabilities typically lack the familiar form and function of the mouse. This thesis details the design and development of a pressure-sensitive device called The Mole. The Mole retains the familiar form and function of the mouse while passively measuring the magnitude of normal hand force (i.e., downward force normal to the 2D operating surface). The measurement of this force lends itself to the development of novel interactions, far beyond what is possible with a typical mouse. This thesis demonstrates two such interactions: the positioning of a cursor in 3D space, and the simultaneous manipulation of cursor position and graphic tool parameters

Improving expressivity in desktop interactions with a pressure-augmented mouse

Desktop-based Windows, Icons, Menus and Pointers (WIMP) interfaces have changed very little in the last 30 years, and are still limited by a lack of powerful and expressive input devices and interactions. In order to make desktop interactions more expressive and controllable, expressive input mechanisms like pressure input must be made available to desktop users. One way to provide pressure input to these users is through a pressure-augmented computer mouse; however, before pressure-augmented mice can be developed, design information must be provided to mouse developers. The problem we address in this thesis is that there is a lack of ergonomics and performance information for the design of pressure-augmented mice. Our solution was to provide empirical performance and ergonomics information for pressure-augmented mice by performing five experiments. With the results of our experiments we were able to identify the optimal design parameters for pressure-augmented mice and provide a set of recommendations for future pressure-augmented mouse designs

Predicting and Reducing the Impact of Errors in Character-Based Text Entry

This dissertation focuses on the effect of errors in character-based text entry techniques. The effect of errors is targeted from theoretical, behavioral, and practical standpoints. This document starts with a review of the existing literature. It then presents results of a user study that investigated the effect of different error correction conditions on popular text entry performance metrics. Results showed that the way errors are handled has a significant effect on all frequently used error metrics. The outcomes also provided an understanding of how users notice and correct errors. Building on this, the dissertation then presents a new high-level and method-agnostic model for predicting the cost of error correction with a given text entry technique. Unlike the existing models, it accounts for both human and system factors and is general enough to be used with most character-based techniques. A user study verified the model through measuring the effects of a faulty keyboard on text entry performance. Subsequently, the work then explores the potential user adaptation to a gesture recognizer’s misrecognitions in two user studies. Results revealed that users gradually adapt to misrecognition errors by replacing the erroneous gestures with alternative ones, if available. Also, users adapt to a frequently misrecognized gesture faster if it occurs more frequently than the other error-prone gestures. Finally, this work presents a new hybrid approach to simulate pressure detection on standard touchscreens. The new approach combines the existing touch-point- and time-based methods. Results of two user studies showed that it can simulate pressure detection more reliably for at least two pressure levels: regular (~1 N) and extra (~3 N). Then, a new pressure-based text entry technique is presented that does not require tapping outside the virtual keyboard to reject an incorrect or unwanted prediction. Instead, the technique requires users to apply extra pressure for the tap on the next target key. The performance of the new technique was compared with the conventional technique in a user study. Results showed that for inputting short English phrases with 10% non-dictionary words, the new technique increases entry speed by 9% and decreases error rates by 25%. Also, most users (83%) favor the new technique over the conventional one. Together, the research presented in this dissertation gives more insight into on how errors affect text entry and also presents improved text entry methods

Integrating Usability Models into Pervasive Application Development

This thesis describes novel processes in two important areas of human-computer interaction (HCI) and demonstrates ways to combine these in appropriate ways. First, prototyping plays an essential role in the development of complex applications. This is especially true if a user-centred design process is followed. We describe and compare a set of existing toolkits and frameworks that support the development of prototypes in the area of pervasive computing. Based on these observations, we introduce the EIToolkit that allows the quick generation of mobile and pervasive applications, and approaches many issues found in previous works. Its application and use is demonstrated in several projects that base on the architecture and an implementation of the toolkit. Second, we present novel results and extensions in user modelling, specifically for predicting time to completion of tasks. We extended established concepts such as the Keystroke-Level Model to novel types of interaction with mobile devices, e.g. using optical markers and gestures. The design, creation, as well as a validation of this model are presented in some detail in order to show its use and usefulness for making usability predictions. The third part is concerned with the combination of both concepts, i.e. how to integrate user models into the design process of pervasive applications. We first examine current ways of developing and show generic approaches to this problem. This leads to a concrete implementation of such a solution. An innovative integrated development environment is provided that allows for quickly developing mobile applications, supports the automatic generation of user models, and helps in applying these models early in the design process. This can considerably ease the process of model creation and can replace some types of costly user studies.Diese Dissertation beschreibt neuartige Verfahren in zwei wichtigen Bereichen der Mensch-Maschine-Kommunikation und erläutert Wege, diese geeignet zu verknüpfen. Zum einen spielt die Entwicklung von Prototypen insbesondere bei der Verwendung von benutzerzentrierten Entwicklungsverfahren eine besondere Rolle. Es werden daher auf der einen Seite eine ganze Reihe vorhandener Arbeiten vorgestellt und verglichen, die die Entwicklung prototypischer Anwendungen speziell im Bereich des Pervasive Computing unterstützen. Ein eigener Satz an Werkzeugen und Komponenten wird präsentiert, der viele der herausgearbeiteten Nachteile und Probleme solcher existierender Projekte aufgreift und entsprechende Lösungen anbietet. Mehrere Beispiele und eigene Arbeiten werden beschrieben, die auf dieser Architektur basieren und entwickelt wurden. Auf der anderen Seite werden neue Forschungsergebnisse präsentiert, die Erweiterungen von Methoden in der Benutzermodellierung speziell im Bereich der Abschätzung von Interaktionszeiten beinhalten. Mit diesen in der Dissertation entwickelten Erweiterungen können etablierte Konzepte wie das Keystroke-Level Model auf aktuelle und neuartige Interaktionsmöglichkeiten mit mobilen Geräten angewandt werden. Der Entwurf, das Erstellen sowie eine Validierung der Ergebnisse dieser Erweiterungen werden detailliert dargestellt. Ein dritter Teil beschäftigt sich mit Möglichkeiten die beiden beschriebenen Konzepte, zum einen Prototypenentwicklung im Pervasive Computing und zum anderen Benutzermodellierung, geeignet zu kombinieren. Vorhandene Ansätze werden untersucht und generische Integrationsmöglichkeiten beschrieben. Dies führt zu konkreten Implementierungen solcher Lösungen zur Integration in vorhandene Umgebungen, als auch in Form einer eigenen Applikation spezialisiert auf die Entwicklung von Programmen für mobile Geräte. Sie erlaubt das schnelle Erstellen von Prototypen, unterstützt das automatische Erstellen spezialisierter Benutzermodelle und ermöglicht den Einsatz dieser Modelle früh im Entwicklungsprozess. Dies erleichtert die Anwendung solcher Modelle und kann Aufwand und Kosten für entsprechende Benutzerstudien einsparen