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Whereas a rightward bump is more likely than a leftward bump when walking through a doorway, investigations into potential similar asymmetries for drivers are limited. The research presented here aims to determine the influence of innate lateral spatial biases when driving. Data from the Strategic Highway Research Program Naturalistic Driving Study (SHRP 2 NDS) and a driving simulation were used to address our research questions. Data points from SHRP 2 were aggregated within relevant variables (e.g., left/right obstacles). In the simulation, participants drove in ways that were consistent with their everyday driving in urban and rural environments. Collision frequency, collision severity and average lateral lane position were analyzed with rightward biases throughout both analyzes. SHRP 2 data indicated greater likelihoods of collisions when vehicles crossed the right line/edge of the road and when making a right turn. There were more collisions with obstacles on the right side, which were also more severe, and greater rightward lane deviations in the driving simulation, contrasted with more severe collisions on the left side in SHRP 2 data, possibly because of the presence of traffic. These findings suggest that previously observed rightward biases in distant space when walking are also present when driving. [ABSTRACT FROM AUTHOR]

Phenotyping is considered a significant bottleneck impeding fast and efficient crop improvement. Similar to many crops, Brassica napus , an internationally important oilseed crop, suffers from low genetic diversity, and will require exploitation of diverse genetic resources to develop locally adapted, high yielding and stress resistant cultivars. A pilot study was completed to assess the feasibility of using indoor high-throughput phenotyping (HTP), semi-automated image processing, and machine learning to capture the phenotypic diversity of agronomically important traits in a diverse B. napus breeding population, SKBnNAM, introduced here for the first time. The experiment comprised 50 spring-type B. napus lines, grown and phenotyped in six replicates under two treatment conditions (control and drought) over 38 days in a LemnaTec Scanalyzer 3D facility. Growth traits including plant height, width, projected leaf area, and estimated biovolume were extracted and derived through processing of RGB and NIR images. Anthesis was automatically and accurately scored (97% accuracy) and the number of flowers per plant and day was approximated alongside relevant canopy traits (width, angle). Further, supervised machine learning was used to predict the total number of raceme branches from flower attributes with 91% accuracy (linear regression and Huber regression algorithms) and to identify mild drought stress, a complex trait which typically has to be empirically scored (0.85 area under the receiver operating characteristic curve, random forest classifier algorithm). The study demonstrates the potential of HTP, image processing and computer vision for effective characterization of agronomic trait diversity in B. napus , although limitations of the platform did create significant variation that limited the utility of the data. However, the results underscore the value of machine learning for phenotyping studies, particularly for complex traits such as drought stress resistance. [ABSTRACT FROM AUTHOR]

All real-time computer games, particularly networked computer games, have a delay from when a player starts an action (e.g., clicking the mouse) until the game renders the result (e.g., firing a projectile). This delay can degrade both player performance (e.g., reduced game score) and quality of experience (e.g., the game is less fun). While previous work has studied the effects of delay on commercial games and individual game actions, a more detailed understanding is needed of the effects of delay on moving target selection with realistic target motion, a common scenario in many games. This paper presents an in-depth study of the effects of delay on the fundamental game action of selecting a moving target with a mouse while varying two parameters for the target motion - turn frequency and turn angle. We design and implement a custom game where players select moving targets using a mouse, while the game controls both the target motion and input delay. Analysis of data gathered in a 56-person user study shows both target selection time and accuracy degrade with delay. However, both selection time and accuracy increase with the frequency and angle of changes in the target's movement, because turning slows targets down even while making them less predictable. We set these results in the context of other studies of delay and target selection by comparing our findings to those in seven other previously published papers that investigated the effects of delay on target selection. [ABSTRACT FROM AUTHOR]

People exhibit consistent leftward spatial biases across a variety of tasks. However, individuals with a native reading direction other than left-to-right (LTR) show an attenuation of the leftward bias. The current study used procedurally similar tasks to examine spatial ability and aesthetic preferences in LTR and right-to-left (RTL) groups. In the spatial task participants viewed a centred rectangle partially occluded by an overlapping circle and estimated the centre of the circle with a single mouse click. In the aesthetic task participants used the mouse to control a "virtual flashlight" to light images of abstract paintings in the most aesthetically pleasing way. Contrary to predictions, smaller errors were made for circles on the right and estimations were progressively less accurate as circle size increased in the spatial task. On the aesthetic task, light placements of LTR participants were biased to the left and significantly different from the slightly rightward placements of RTL participants. As predicted, when completing the aesthetics task amounts of time scanning left or right visual space were different between groups. Findings support the theory that directional scanning biases attenuate leftward lateral biases and further, the nature of the visuospatial task may vary the strength of lateral bias. [ABSTRACT FROM AUTHOR]

Leadership is considered critical to virtual community success. Leaders engage in important community activities such as encouraging members and building social structure. These potential benefits, however, have rarely been empirically tested. We were presented with an opportunity to explore this issue while studying an online board-and-card-game community. During our study, the community experienced a major change in leadership when the founder - and formal leader - decided to substantially reduce his involvement in the site. This provided us with the rare opportunity to carry out a case study of leadership reduction in a real-world community. To look at the effects of leadership on community behaviour, we analysed 16 months of activity logs, supported by interviews, to compare the community before, during, and after the founder's withdrawal. We observed strong variability in the effects of a leadership reduction - some results were in line with the 'leadership hypothesis,' but others were unexpected. In some cases, we found evidence that reducing formal leadership can have negative effects on the success of the community; but in other cases, we found surprising sources of resilience to the reduction in leadership activities. Our study is the first to look at the details of how leadership (and a reduction in this role) affects several types of sub-community within a board-and-card game site, and the first to consider some of the factors that lead to differences in the effects of leadership reduction. Overall, we found that negative effects on sub-communities were closely tied to the specific activities that the leader provided, and the degree to which he was the only person able to provide those roles. The broad strokes of this finding agree with the leadership hypothesis, but there are several unexpected elements within the main story: the negative effects were less drastic than we anticipated, and all of the sub-communities (even the most dependent) survived the transition. The strong resilience of some of the sub-communities seems to be connected to their ability to 'fall back' to a foundation of shared activity (i.e., game play) - an idea that has been introduced in earlier work but never studied empirically. This research helps designers to understand the complexities of leadership in online communities, providing an important foundation for developing and supporting online groups. [ABSTRACT FROM AUTHOR]

We-awareness is the socially recursive inferences that let collaborators know that all are mutually aware of each other's awareness. While we-awareness is easy afforded in face to face collocated collaboration, it is much more difficult to design distributed groupware tools to provide equivalent capabilities: there can be no awareness unless it is programmed in via system features. We identify a series of questions that must be considered if we-awareness is to be supported. What types of awareness information is crucial and should thus be added to the 'blank slate' of a screen sharing system? How can that awareness information be captured through technology, and what information will be lost during this capture process? How should that information be translated, transformed and encoded into a digital form, and-as part of that-what information will be altered as part of that translation process? How will that information be transmitted, and what are the network effects in terms of that information being received in a timely manner? How will that information be represented to other participants in order to enable the rich and subtle interactions that occur in the face-to-face setting? We illustrate the nuances of these questions and why they are difficult to answer by revisiting several prior technical solutions to we-awareness. [ABSTRACT FROM AUTHOR]

Identifying a target command can be difficult and time-consuming when the user is unfamiliar with a software system. One technique for assisting command identification is to provide asubset interfacethat contains only a limited set of the system's capabilities. We examine the design of subset interfaces, showing that subsets can be presentedseparatelyto the full user interface (UI) (e.g. in a palette) orin place, with in-place methods using eitherstaticordynamicmethods to identify the subset. We introduce theStencilMapandEphemeralMapasin-placesubset UIs that, respectively, use static and dynamic highlighting. Both StencilMaps and EphemeralMaps make all of an application's commands concurrently available for selection within a grid. To highlight subset items StencilMaps use a static dark semi-transparent ‘stencil’ overlay to de-emphasise all but the subset items; EphemeralMaps, in contrast, use a short delay, with subset items shown immediately, and other items gradually faded in. A first experiment compares user performance with thein-placepresentation of StencilMaps against that of theseparatepresentation of a subset palette. Results confirm the predicted spatial memory benefits for StencilMaps. A second experiment analyses the performance impact of three approaches to highlighting: none,statichighlighting in StencilMaps, anddynamichighlighting in EphemeralMaps. Results show an interesting trade-off – while highlighting can offer benefits in assisting rapid target identification (particularly when the user is unfamiliar with the interface layout), there can also be longer-term performance benefits when highlighting is absent because the increased difficulty of visual search promotes the use and formation of spatial memory. [ABSTRACT FROM PUBLISHER]

Interface design guidelines encourage designers to provide high-performance mechanisms for expert users. However, research shows that many expert interface components are seldom used and that there is a tendency for users to persistently fail to adopt faster methods for completing their work. This article summarizes and organizes research relevant to supporting users in making successful transitions to expert levels of performance. First, we provide a brief introduction to the underlying human factors of skill acquisition relevant to interaction with computer systems. We then present our focus, which is a review of the state of the art in user interfaces that promote expertise development. The review of interface research is based around four domains of performance improvement: intramodal improvement that occurs as a factor of repetition and practice with a single method of interaction; intermodal improvement that occurs when users switch from one method to another that has a higher performance ceiling; vocabulary extension, in which the user broadens his or her knowledge of the range of functions available; and task mapping, which examines the ways in which users perform their tasks. The review emphasizes the relationship between interface techniques and the human factors that explain their relative success. [ABSTRACT FROM AUTHOR]