This research study examined the design of a virtual keyboard that can be used for text entry with a rotary controller, particularly when users may differ in age and experience with a particular system. I specifically examined the shape and letter arrangement on the virtual keyboard to help determine the best features to use in a design. Two keyboard shapes, an Oval and a Plus, were selected to represent different aspects of the shape. Two keyboard arrangements, Alphabetic and a Standard QWERTY-based ordering, were selected to represent a well-known and less familiar arrangement. In the experiment, older and younger adults entered words over two consecutive days. Most of the time, they used either the Oval or the Plus, but they also used the alternate shape at specific points during their practice session to allow assessment of their ability to transfer what they had learned. At the end of the second day, they also used a variation of the practiced arrangement to examine how well they had learned the letter arrangement. Text entry performance on both shapes improved as a function of practice, demonstrating that participants could learn even unfamiliar devices and virtual keyboards to complete a word entry task. No overall shape effects were found for any level of performance, but shape did affect how participants learned and performed the word entry task. In particular, unique visual features on a shape may facilitate memorization of letter/visual cue mappings. These shape features are particularly important for older adults, as younger adults seem to develop a mental model that helps them memorize letter locations on either shape. With practice, older adults could achieve optimal performance levels with an Alphabetic keyboard on the Plus shape that has the more visually unique corners. In general, alphabetic ordering is best not only because it helped visual search, but also because it facilitated better movement planning. Overall, designers should consider creating unique visual features on a virtual keyboard that will blend with the compatibility and allowed movements for the selected device to create an effective virtual keyboard.

Internet users are increasingly required to sign up for online services and establish accounts before receiving service from websites. On the one hand, generation of strong usernames and passwords is a difficult task for the user. On the other hand, memorization of strong passwords is by far more problematic for the average user. Thus, the average user has a tendency to use weak passwords, and also reuse his passwords for more than one website, which makes several attacks feasible. Under the aforementioned circumstances, the use of password managers is beneficial, since they unburden the user from the task of memorizing user credentials. However, password managers have a number of weaknesses. This thesis is mainly aimed at alleviating some of the intrinsic weaknesses of password managers. We propose three cryptographic protocols which can improve the security of password managers while enhancing user convenience. We also present the design of a phishing and Man-in-the-Browser resistant password manger which best fits into our scheme. Furthermore, we present our novel virtual on-screen keyboard and keypad which are designed to provide strong protection mechanisms against threats such as keylogging and shoulder surfing.

3D is a popular topic as an increasing amount of media and technology begin to support 3D interaction.  With the rise of interest in 3D interaction, the question of why there is a demand and desire for 3D over 2D interaction becomes relevant. This thesis compares the differences between a 3D heads up display and a 2D heads up display for a touch free gesture based virtual keyboard.  The gesture interface used in the tests is a way of communicating with a system using gestures of the hands tracked by a motion sensor.  This thesis tested 16 users where half of the users used a 2D version of a heads up display and the other half used a 3D version of a heads up display.  Both user groups were tested with identical conditions and in an identical environment.  Raw statistical data was gathered from a logging mechanism in the interface and qualitative data was gathered from questionnaires and observation notes.  The results from the experiment showed that the 2D and 3D heads up display gave very similar results. However, results also showed slightly better qualitative results from the 3D heads up display observation and questionnaire data.  The conclusion indicated no clear advantage for the 2D version or the 3D version.  The discussion shows that many other factors in the design process and selection of users, play a large role in the comparison of 2D vs 3D visualizations.  Factors such as age and familiarity with different levels of technology are indicated to be contributing factors when comparing 2D vs 3D.  The results and discussion hope to provide a starting point for future comparison research in the field of 2D compared to 3D visualization.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 62-65). Also available via the Internet.

Characters on computer keyboards are typically printed using one of the two different processes, namely tampographic printing and laser marking. Tampographic printing is time consuming (app. 3-5 mins.), requires skilled workers and employs difficult-to-handle chemicals. On the other hand, the laser marking process is rapid «1 min.), relatively cheap, avoids the need for chemicals and can be carried out with fewer, less skilled operatives than required fortampographic printing. Data from a keyboard production company indicated that there has been a sudden decline in the percentage (from 60% in 2001 to less than 10% in 2003) of laser marked keyboard users over recent years due to a lack of initial contrast of white characters on a dark plastic and poor durability. Under usual office conditions, characters that are used more regularly e.g. 'e' or 's', can be erased in less than 3-6 months. Further, generating a durable high contrast laser mark on dark coloured polymers has also long been an issue. The thesis initially reports on an investigation into the reasons for lack of initial contrast and subsequent discolouration of laser marked and tampo printed characters. This is followed by the development of a range of plastics compounds based on ABS and containing a series of different additives. Criteria for selecting additives that would respond appropriately to a laser are also proposed. The compounds were laser marked under a 1064nm Nd:YAG laser at different power, frequency and speed settings. Plaques of the material were manufactured and laser marked in a grid-like pattern to study both the effect of frequency and speed of marking. The mechanisms associated with the laser-material interaction during the marking process were also investigated using light microscopy and scanning electron microscopy. Microscopy was also employed toobserve the morphology of the marks left by the laser. Finally a unique test regime was designed to characterise the durability of the laser markings under conditions that attempt to simulate those experienced in practice. Results show that aluminium trihydroxide generated superior contrast and exhibited enhanced durability characteristics when compared with nine other micro-additives. Nano-additives, such as nano titanium dioxide portrayed better contrast and durability performance when compared to their micro-size additive equivalents. Analysis of the test plaque results clearly demonstrated that for a specific material compound, it is possible to optimise the laser settings to achieve the best combination of character contrast and durability. Finally, this work is believed to have made a significant contribution to the rather sparse laser markable polymers research field. It will assist in the development of a more fundamental understanding of laser/material interactions and provide a basis for future work in optimising materials formulations for successful laser marking.

Internet users are increasingly required to sign up for online services and establish accounts before receiving service from websites. On the one hand, generation of strong usernames and passwords is a difficult task for the user. On the other hand, memorization of strong passwords is by far more problematic for the average user. Thus, the average user has a tendency to use weak passwords, and also reuse his passwords for more than one website, which makes several attacks feasible. Under the aforementioned circumstances, the use of password managers is beneficial, since they unburden the user from the task of memorizing user credentials. However, password managers have a number of weaknesses. This thesis is mainly aimed at alleviating some of the intrinsic weaknesses of password managers. We propose three cryptographic protocols which can improve the security of password managers while enhancing user convenience. We also present the design of a phishing and Man-in-the-Browser resistant password manger which best fits into our scheme. Furthermore, we present our novel virtual on-screen keyboard and keypad which are designed to provide strong protection mechanisms against threats such as keylogging and shoulder surfing.

Three major principles of learning a chord keyboarding task were investigated. Five subjects were taught 18 characters on a chord keyboard, then practiced improving their keying speed for about 60 hours. The first objective of the study was to observe long-term learning on a keyboarding task. The performance, in characters typed per minute, was recorded over the entire range of the experiment. Typing skill improved quickly in the beginning and then slowed, but performance had not reached a stable peak by the end of the experiment. The second objective of this study was to determine a function that describes performance progress from initial training to a high keying speed. Five functions were evaluated; a function which predicts the logarithm of the dependent variable (characters per minute) from the logarithm of the regressor variable provided a good fit to the actual data. The final form of the equation was CPM; = e^B₀T_i^B₁ where CPM_i; = performance in characters per minute on the i-th interval, T_i = the i-th interval of practice, and B₀ and B₁ are fitted coefficients. The second objective also considered the form that T_i (from the above equation) should take. Performance can be predicted from number of repetitions such as trials, or from amount of practice such as hours. Both trials and time were used as predictor variables and both provided equally accurate predictions of typing speed. Both also provided excellent fits in conjunction with the Log-Log equation. Thus, it appears the Log-Log function is fairly robust in predicting performance from different variables. The third objective was to investigate how many trials of performance are needed before the entire learning function can be reasonably determined. In this experiment, subjects practiced for an extended period of time (about 60 hours) so a fairly complete progression of performance could be gathered. Yet, it would be more convenient to collect data for only a few hours and deduce the ensuing performance of the subject. The coefficients of the Log-Log function were determined using only the first 25, 50, 100, 150, and 200 of the initial performance points (out of about 550 total actual data points). The mean squared error (MSE) was calculated for each of these fits and compared to the MSE of the fit using all points. It appears that at least 50 performance data points are required to reduce the error to a reasonably acceptable level. / Master of Science

In the last several years, there has been an interest in graphical user interfaces as compared with character user interfaces. The "mouse" is the device most closely associated with graphical user interfaces. Key strokes are more closely associated with character user interfaces. Given these associations, is there a preference for the keyboard or for the mouse as an input device? The determination of user preference was reduced to the determination of preference of key strokes or mouse clicks for selection of main menu items. The subjects, university students working with Microsoft Works by Microsoft Corporation, copyright 1987-1989, were learning how to use application software. While Microsoft Works was running, tracking software recorded every user key stroke and mouse click, together with data about these key strokes and mouse clicks. From the analysis of these data, common preference for the means of menu item selection was determined.

The information technology that is available now has been developed for other populations, such as the general public, the business community, health care organizations, or the handicapped. However, much of it can be adapted to fit the needs, desires and capabilities of the elderly and computer technology can be much "friendlier" for the elderly in both a technological and a social sense. This study examines the elderly-computer technology interface. State-of -the-art computer input devices are evaluated and an ergonomic analysis is made about the interface. Finally, a new design concept is developed to solve the problems and complications arising from the aging process in terms of accessibility, safety, efficiency, ergonomic comfort of computer technology and to introduce a new and fairly unfamiliar technology to a population group. / Master of Science

Este trabalho descreve um ataque que detecta as teclas pressionadas em teclados mecânicos pela análise das vibrações geradas quando as mesmas são pressionadas. Dois equipamentos foram experimentados no ataque: um teclado genérico de automação comercial e um terminal de ponto de venda (POS / PIN-pad). Acelerômetros são utilizados como sensores de vibração. Propositalmente, o equipamento necessário para a execução do ataque é de baixíssimo custo, de modo a ressaltar o risco das vulnerabilidades encontradas. Obtivemos taxas de sucesso médio de 69% no reconhecimento das teclas pressionadas para o terminal PIN-pad em repouso e 75% para o mesmo sendo segurado na mão. No caso de teclado de automação comercial, as taxas médias de acerto ficaram em torno de 99%. / This work describes an attack that identifies the sequence of keystrokes analyzing mechanical vibrations generated by the act of pressing keys. We use accelerometers as vibration sensors. The apparatus necessary for this attack is inexpensive and can be unobtrusively embedded within the target equipment. We tested the proposed attack on an ATM keypad and a PIN-pad. We achieved the key recognition rates of 99% in ATM keypad, 69% in PIN-pad resting on a hard surface and 75% in PIN-pad hold in hand.