Abstract:
Keyboard and mouse are often used as primary input devices when users choose to work with high-interactivity applications. For textual applications, the keyboard is used for typing, while the mouse is commonly used for cursor placement within the text. The continuous flipping of hands between the two devices is often irritating and disrupts the workflow. Excessive use of these devices can also lead to musculoskeletal disorders in the wrists and hands. Exploration of a new interaction medium that works in conjunction with conventional user interfaces could benefit many users. Gaze as an input has a lot of potential as it potentially requires no training and is natural and easy to use. Gaze indicates the user’s attention and typically precedes actions that require using input devices. With advances in hardware and software, eye gaze tracking may soon come as an inbuilt standard feature of the new generation of computing devices, especially the desktop. Now imagine you spot a typo you need to correct. What would you expect from a natural user interface (NUI)? That you still have to use the mouse to point to the typo, although you are already looking at it? This thesis proposes ReType, a NUI paradigm integrating keyboard with gaze: you look at the place you want to edit and ‘re-type’ the text as you want it, including a short lead-up to the changed characters. This is similar to how we speak about typos while we correct them. ReType, the novel gaze-assisted technique, helps to facilitate mouse-free cursor positioning and text editing, saving the user from frequent hand switches between keyboard and mouse. This thesis presents the three-stage development of ReType. In the first stage, the initial design of the prototype as a standalone gaze-enabled text editor is proposed. This variant, relying on explicit mode switches, is named ‘modal ReType’. An informal user study shows that the prototype received positive and encouraging feedback. Participants felt they had good control over the system and were able to edit text at a speed similar to when they use a mouse. In response to feed back, the second stage presents ‘automatic ReType’, which allows gaze-enabled automatic switching between the editing and default typing modes. Qualitative and quantitative user studies indicate that ReType enhances the user experience of text editing and was preferred by most participants. It was observed that professional keyboard users (such as touch typists) benefited particularly from the system. By avoiding keyboard–mouse switches, ReType allowed users to focus on the keyboard and make better use of their typing skills. In terms of speed, ReType was able to match or even beat the speed of mouse-based interaction for small text edits. Lastly, seeing that Microsoft Word enjoys a huge market base as a word processing software and is highly popular among professional users, the third stage introduces ReType as a Microsoft Word plugin. The plugin makes it possible to use Microsoft Word features together with gaze-enabled text interaction for error correction, text selection and navigation. A short-term field study indicated that ReType helped participants to remain focused and productive, especially when fixing typing errors. Most participants stated that they would use ReType if it becomes available. All in all, to the best of our knowledge, ReType is currently the best gaze-operated text editing system for the general population of computer users.