Optimization of Switch Virtual Keyboard by Using Computational Modelling

In this thesis, I first reviewed some keyboard technologies used by people with motor difficulties, and described design elements that influence efficiency. I cast the design of a switch keyboard as an optimization problem, and arrangement of keys on such a keyboard as a Mixed Integer Programming problem. One significant variable in the MIP problem, the error rate, is related to several other variables. I treated modeling of the error rate as a parameter estimation problem, and used a data mining method. I designed HCI experiments to gather data for parameter estimation, using Bayesian logistic regression model. The empirical data and error rate modeling allowed for construction of several different types of keyboards. These different keyboards were compared and evaluated with regard to their use by people with motor difficulties

Payload crew interface design criteria and techniques. Task 1: Inflight operations and training for payloads

Guidelines are developed for use in control and display panel design for payload operations performed on the aft flight deck of the orbiter. Preliminary payload procedures are defined. Crew operational concepts are developed. Payloads selected for operational simulations were the shuttle UV optical telescope (SUOT), the deep sky UV survey telescope (DUST), and the shuttle UV stellar spectrograph (SUSS). The advanced technology laboratory payload consisting of 11 experiments was selected for a detailed evaluation because of the availability of operational data and its operational complexity

FlexType: Flexible Text Input with a Small Set of Input Gestures

In many situations, it may be impractical or impossible to enter text by selecting precise locations on a physical or touchscreen keyboard. We present an ambiguous keyboard with four character groups that has potential applications for eyes-free text entry, as well as text entry using a single switch or a brain-computer interface. We develop a procedure for optimizing these character groupings based on a disambiguation algorithm that leverages a long-span language model. We produce both alphabetically-constrained and unconstrained character groups in an offline optimization experiment and compare them in a longitudinal user study. Our results did not show a significant difference between the constrained and unconstrained character groups after four hours of practice. As expected, participants had significantly more errors with the unconstrained groups in the first session, suggesting a higher barrier to learning the technique. We therefore recommend the alphabetically-constrained character groups, where participants were able to achieve an average entry rate of 12.0 words per minute with a 2.03% character error rate using a single hand and with no visual feedback

Human factors analysis of workstation design: Earth Radiation Budget Satellite Mission Operations Room

A human factors analysis addressed three related yet distinct issues within the area of workstation design for the Earth Radiation Budget Satellite (ERBS) mission operation room (MOR). The first issue, physical layout of the MOR, received the most intensive effort. It involved the positioning of clusters of equipment within the physical dimensions of the ERBS MOR. The second issue for analysis was comprised of several environmental concerns, such as lighting, furniture, and heating and ventilation systems. The third issue was component arrangement, involving the physical arrangement of individual components within clusters of consoles, e.g., a communications panel

Shortlinks and tiny keyboards: a systematic exploration of design trade-offs in link shortening services

Link-shortening services save space and make the manual entry of URLs less onerous. Short links are often included on printed materials so that people using mobile devices can quickly enter URLs. Although mobile transcription is a common use-case, link-shortening services generate output that is poorly suited to entry on mobile devices: links often contain numbers and capital letters that require time consuming mode switches on touch screen keyboards. With the aid of computational modeling, we identified problems with the output of a link-shortening service, bit.ly. Based on the results of this modeling, we hypothesized that longer links that are optimized for input on mobile keyboards would improve link entry speeds compared to shorter links that required keyboard mode switches. We conducted a human performance study that confirmed this hypothesis. Finally, we applied our method to a selection of different non-word mobile data-entry tasks. This work illustrates the need for service design to fit the constraints of the devices people use to consume services

Hand-printed input for on-line systems

Recognition program for handwritten information in real time computer operatio

An adaptable scan-based text entry for mobile devices: Design, predictive modeling, and empirical evaluation

This paper presents a highly customizable assistive on-screen keyboard for mobile devices, which supports several text entry methods based on row-column and bisection scanning techniques. Text entry can be accomplished using a zone based touch screen interface and/or via hardware keypads, involving configurable input control which can range from single-switch solution up to 5-key design. Apart from the presentation of a novel user interface, the paper contributions are as follows: development of movement models for all scan-based methods involved in text entry solution, computation of related upper-bound text entry speed predictions, and empirical investigation of their validity. In order to assess model predictions, a specific instance of row-column scanning technique was juxtaposed to bisection scanning principle in a user study involving 16 participants. Methods are evaluated against text entry performance, required workload, and general usability attributes. Although theoretical models predicted higher entry speed for bisection scanning, the results obtained from experiment demonstrated the row-column technique as significantly more efficient. This outcome discrepancy is specifically discussed by putting emphasis on factors that affect identified relation.