Thesis (Ph. D.)--Northeastern University, 2007. / Graduate School of Computer and Information Science. Includes bibliographical references (p. 106-113).

Thesis (Ph. D.)--Northeastern University, 2007. / Graduate School of Computer and Information Science. Also available electronically. Includes bibliographical references (p. 106-113).

Chord keyboards use the concept of simultaneous activation of keys to produce single characters. Some chord keyboards have been suggested as potential devices to replace the standard QWERTY keyboard which is now considered the major human-computer interface tool. This study focused on evaluating a new chord keyboard that uses a set of eight ternary (3 state) keys. An experimental comparison of the ternary chord keyboard (TCK) with the QWERTY keyboard was conducted. Two groups of subjects were selected to participate in the study. One group was assigned to the QWERTY keyboard and the other to the TCK. The two groups learned to input a set of 17 characters. Training of each group was similar and the stimuli were identical. The study investigated how the two groups compared in attaining certain performance criteria (speed and accuracy), and how performances compared on both keyboards after fulfilling the criteria. For each group, the number of sessions to reach the criteria was recorded along with speed and accuracy of typing. At the end of the experimental session, subjects rated some features of their respective keyboard. Performances on both keyboards were comparable in all stages with no significant differences revealed. However, executing chords on the TCK was rated significantly more difficult than activating keys on the QWERTY keyboard. / Master of Science

In a pilot study, response times of 64 possible chords on the Ternary Chord Keyboard (TCK) were compared in order to establish a basis for assigning characters to chords. It was found that subjects had faster response times for some chords than others. Upon close inspection of the experimental procedure, it appeared that the way in which the chords were cued caused part of the differences in response time, which had been expected to depend only on chord motor differences. The present study was designed to examine the hypotheses that chord cueing caused part of the differences in chord response times, and that this effect of cueing is consistent over practice; and also the hypothesis that the results of the pilot study reflected the motor (movement time) difference between chords, and that the difference itself is consistent over practice. This was done in the framework of Sternbcrg's Additive Factors Method. lt was found that the cueing scheme used in the pilot study did not cause the differences in chord response times. However, the differences in chord movement time was not reflected by the use of the pilot study paradigm. This technique should therefore not be used in ordering chords according to chord case. / Master of Science

The use of mobile bar code scanners is expanding to markets beyond popular manufacturing uses, such as healthcare, environmental testing and professional services. The successful interaction of users with mobile bar code scanners is of great importance from a business and technology perspective as well as from the user standpoint. Interaction problems associated with these devices may cause errors in data collection and affect job performance due to frustration, resulting in a potential impact on internal costs. The primary objective of this research was to develop design guidelines for the reengineering of keyboard designs for mobile bar code scanners. A secondary objective was to determine the effectiveness of current bar code scanner designs and how they can be related to other mobile technologies to develop a link across research areas. To accomplish these objectives, three different mobile bar code scanner keyboard designs were investigated: multiple-alphabetical, single-alphabetical and single split-Qwerty. A total of 42 subjects (18 females and 24 males) were recruited to participate in the experiment that was conducted to validate the research hypotheses. Time and accuracy data were recorded during the experiment and workload/subjective questionnaires were given to each participant following interaction with the different mobile bar code scanners. The following conclusions were reached based on the experimental results and are considered the major contributions of this research. First, an alphabetically laid out keyboard with multiple keys results in more time to find a character, a higher percentage of time spent typing incorrect lines, and a higher error rate than an alphabetically laid out keyboard with single keys. Perceived workload was also higher for a keyboard with multiple keys versus one with single keys. Second, no significant differences were found in the time to find a character, the percentage of time spent typing incorrect lines, and the error rate between keyboards with single keys, whether they are laid out alphabetically or in a split-Qwerty design. Finally, training a user on how to use a specific mobile bar code scanner keyboard layout often results in higher character rates, less time spent typing incorrect lines, and a lower error rate. / Graduation date: 2006

No description available.

Thesis (M.Sc.)--York University, 2007. Graduate Programme in Computer Science and Engineering. / Typescript. Includes bibliographical references (leaves 83-88). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR29276

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 132-136). Also available via the Internet.

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.

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