Físchlár on a PDA: handheld user interface design to a video indexing, browsing and playback system

The Físchlár digital video system is a web-based system for recording, analysis, browsing and playback of TV programmes which currently has about 350 users. Although the user interface to the system is designed for desktop PCs with a large screen and a mouse, we are developing versions to allow the use of mobile devices to access the system to record and browse the video content. In this paper, the design of a PDA user interface to video content browsing is considered. We use a design framework we have developed previously to be able to specify various video browsing interface styles thus making it possible to design for all potential users and their various environments. We can then apply this to the particulars of the PDA's small, touch-sensitive screen and the mobile environment where it will be used. The resultant video browsing interfaces have highly interactive interfaces yet are simple, which requires relatively less visual attention and focusing, and can be comfortably used in a mobile situation to browse the available video contents. To date we have developed and tested such interfaces on a Revo PDA, and are in the process of developing others

From Server to PDA: An HCI Perspective on Porting Wireless Roaming Business Applications

Advances in processor design, display technology, and lithium polymer batteries have led to a new generation of powerful, compact, and highly mobile devices. There is a range of different physical interfaces available, from the original Palm Pilots and Psion Organisers to the new generation of pocket PCs and personal digital assistants (PDA's). We focus on the stylus/touch-screen-based Compaq iPaq PDA. Combining a PDA with wireless communication technology has the potential for extending the application of computing in business. Many businesses already use handheld data recording devices. A drawback is the need to return the device to a computer to upload the information into the system, where it can be processed and made available to other applications. Using wireless devices this delay can be removed, providing a more accurate and up-to-date data repository. In order to see how a desktop to PDA migration might be carried out, a prototype interface to a mainstream accounting and stock control system was built to run on a Compaq iPaq 3850. Some of the problem areas of migrating server/desktop functionality to handheld devices, including wireless communication, device limitations, and security were demonstrated and explored with this interface. The informal feedback from the users will be fed into a redeveloped version of the system which will then be evaluated using a formal experiment The main lesson learnt was that providing desktop/server functionality on a mobile device requires more than copying a system's existing functionality and shrinking the interface to fit on a smaller screen. User feedback from a prototype system supported the idea that applications benefit from a redesign process when being ported to a mobile environment

Ergonomic, adaptable keyboard for fast data entry on mobile computing devices

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.Includes bibliographical references (leaves 22-24).The usefulness of modem portable computational devices such as cellular phones and portable digital assistants (PDAs) is currently limited by the lack of an effective method for text entry. The currently available input options (such as the 12-key phone pad and PDA touch screens) are a quarter to a third of the speed of the standard desktop QWERTY keyboards. Therefore, it is slow and frustrating for people to use these systems for any significant text input, such as writing emails, taking notes in a meeting, or writing down thoughts while on-the-go. The proposed solution is a one-handed, hand-held, wireless, portable keyboard that would allow the mobile device user to achieve speeds closer to the desktop standard while performing text-entry tasks. Previously developed handheld input devices employ unfamiliar typing systems, are too large, or are not ergonomically comfortable, which may be the reasons they have not been widely adopted by the public. The device described in this paper is small enough to store in one's pocket, is inconspicuous during use, and is adjustable so that the keys reach the fingers in their natural curved position. One interface point allows each finger to control multiple buttons thereby preventing the fingers from, needing to move into uncomfortable positions.(cont.) These features were incorporated into a prototype that proves the feasibility of a compact and comfortable hand-held keyboard. The device also has potential as an ergonomic replacement to the standard desktop keyboard. Unlike traditional keyboards it allows the typist to be relaxed and mobile eliminating some risk factors for repetitive strain injury.by Alexander Mekelburg.S.B

Nomadic input on mobile devices: the influence of touch input technique and walking speed on performance and offset modeling

In everyday life people use their mobile phones on-the-go with different walking speeds and with different touch input techniques. Unfortunately, much of the published research in mobile interaction does not quantify the influence of these variables. In this paper, we analyze the influence of walking speed, gait pattern and input techniques on commonly used performance parameters like error rate, accuracy and tapping speed, and we compare the results to the static condition. We examine the influence of these factors on the machine learned offset model used to correct user input and we make design recommendations. The results show that all performance parameters degraded when the subject started to move, for all input techniques. Index finger pointing techniques demonstrated overall better performance compared to thumb-pointing techniques. The influence of gait phase on tap event likelihood and accuracy was demonstrated for all input techniques and all walking speeds. Finally, it was shown that the offset model built on static data did not perform as well as models inferred from dynamic data, which indicates the speed-specific nature of the models. Also, models identified using specific input techniques did not perform well when tested in other conditions, demonstrating the limited validity of offset models to a particular input technique. The model was therefore calibrated using data recorded with the appropriate input technique, at 75% of preferred walking speed, which is the speed to which users spontaneously slow down when they use a mobile device and which presents a tradeoff between accuracy and usability. This led to an increase in accuracy compared to models built on static data. The error rate was reduced between 0.05% and 5.3% for landscape-based methods and between 5.3% and 11.9% for portrait-based methods