Assessing design features of virtual keyboards for text entry

OBJECTIVE: The present research examined design of a virtual keyboard for text entry with a rotary controller, emphasizing users who differ in age and system experience. BACKGROUND: Existing research has minimally addressed usage frequency, age, and the effects of display shape and letter arrangement on movement and visual search components of text entry tasks. The present research was conducted to close these gaps. METHOD: Two experiments were completed to examine younger (18-28 years) and older (60-75 years) adults' movement and visual search capabilities using four keyboard shapes and three keyboard arrangements. In a third experiment examining combined effects on shape design, 32 younger (18-28 years) and 32 older (60-75 years) adults entered words on the two best shapes from the first experiments. RESULTS: For the movement task, movement time was lowest for shapes with higher shape-controller compatibility. For the visual search task, search time and accuracy were best on the alphabetic arrangement. In the combined task, shape did not significantly influence performance at different levels of practice. Transfers, however, suggested that the shape with salient visual features elicited a text entry strategy for older adults that may promote more consistent performance under occasional usage. CONCLUSION: The studies together demonstrate that keyboard shape is important for efficient performance. Shape-controller compatibility facilitated performance in both age groups. Salient features facilitate performance, especially for older adults. In nearly all cases alphabetic arrangement yielded the best performance. APPLICATION: Recommendations are provided for virtual keyboard design for different usage frequencies, contexts, and users.     

Hyperspectral Imager for the Coastal Ocean: instrument description and first images

The Hyperspectral Imager for the Coastal Ocean (HICO) is the first spaceborne hyperspectral sensor designed specifically for the coastal ocean and estuarial, riverine, or other shallow-water areas. The HICO generates hyperspectral images, primarily over the 400-900 nm spectral range, with a ground sample distance of ≈90 m (at nadir) and a high signal-to-noise ratio. The HICO is now operating on the International Space Station (ISS). Its cross-track and along-track fields of view are 42 km (at nadir) and 192 km, respectively, for a total scene area of 8000 km(2). The HICO is an innovative prototype sensor that builds on extensive experience with airborne sensors and makes extensive use of commercial off-the-shelf components to build a space sensor at a small fraction of the usual cost and time. Here we describe the instrument's design and characterization and present early images from the ISS.