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The present study examined how task priority influences operators' scanning patterns and trust ratings toward imperfect automation. Previous research demonstrated that participants display lower trust and fixate less frequently toward a visual display for the secondary task assisted with imperfect automation when the primary task demanded more attention. One account for this phenomenon is that the increased primary task demand induced the participants to prioritize the primary task than the secondary task. The present study asked participants to perform a tracking task, system monitoring task, and resource management task simultaneously using the Multi-Attribute Task Battery (MATB) II. Automation assisted the system monitoring task with 70% reliability. Task load was manipulated via difficulty of the tracking task. Participants were explicitly instructed to either prioritize the tracking task over all other tasks (tracking priority condition) or reduce tracking performance (equal priority condition). The results demonstrate the effects of task load on attention distribution, task performance and trust ratings. Furthermore, participants under the equal priority condition reported lower performance-based trust when the tracking task required more frequent manual input (tracking condition), while no effect of task load was observed under the tracking priority condition. Task priority can modulate automation trust by eliminating the adverse effect of task load in a dynamic multitasking environment. [ABSTRACT FROM AUTHOR]

Objective: We searched for the application of usability in the literature with a focus on adoption, measurements employed, and demonstrated value. Five human factors domains served as a platform for our reflection, which included the last 20 years. Background: As usability studies continue to accumulate, there has been only a little past reflection on usability and contributions across a variety of applications. Our research provides a background for general usability, and we target specific usability research subareas within transportation, aging populations, autistic populations, telehealth, and cybersecurity. Method: "Usability" research was explored across five different domains within human factors. The goal was not to perform an exhaustive review but, rather, sample usability practices within several specific subareas. We focused on answering three questions: How was usability adopted? How was it measured? How was it framed in terms of value? Conclusion: We found that usability is very domain specific. Usability benchmarking studies and empirical standards are rare. The value associated with improving usability ranged widely—from monetary benefits to saving lives. Thus, researchers are motivated to further improve usability practices. A number of data collection and interpretation challenges still call for solutions. Application: Findings offer insight into the development of usability, as applied across a variety of subdomains. Our reflection ought to inform future theory development efforts. We are concerned about the lack of established benchmarks, which can help ground data interpretation. Future research should address this gap in the literature. We note that our findings can be used to develop better training materials for future usability researchers. [ABSTRACT FROM AUTHOR]

Graphical authentication schemes offer a more memorable alternative to alphanumeric passwords. However, they have been criticized for being susceptible to over-the-shoulder attacks (OSA). To solve this shortcoming, schemes have specifically been designed to be resistant to OSA. Common strategies used to decrease the ease of OSAs are grouping targets among distractors, translating them to another location, disguising the appearance of targets, and using gaze-based input. We are the first to provide a direct comparison of the common strategies regarding usability and OSA resistance. Specifically, we examined three OSA resistant graphical schemes, an eye tracker scheme, and a traditional alphanumeric password. To capture usability performance, we measured login times, learnability, memorability, satisfaction, acceptability, and error rates. OSA performance was examined to determine the relative resistance of each scheme. We found that graphical schemes are memorable after three weeks, and they were resistant to OSAs. Login time was acceptable for some schemes and not others. Learnability and satisfaction were disappointing, and error rates were high likely due to the novelty of these graphical schemes. Alphanumeric passwords offer the best learnability. [ABSTRACT FROM AUTHOR]

In an attempt to provide users with more information while maintaining a calm ubiquitous environment, researchers have investigated the possibility of presenting information "subliminally." The authors explores the historical issues associated with examining perception without awareness with special emphasis on the difficulty associated with ensuring stimuli have been presented below the participant's subjective threshold of awareness. It may be possible to circumvent this issue by taking a results-oriented approach. However, the advancement of subliminal techniques requires stronger experimental evidence that information is actually being presented below the subject threshold of awareness and gaining the desired effect on user performance. The authors offers three considerations that help designers weigh the costs and benefits of employing a subliminal technique. The authors also offers three recommendations that help designers present information below the subjective threshold of awareness and measure their users' awareness of the information. [ABSTRACT FROM AUTHOR]

Affordances are design clues that allow users to effortlessly determine how objects should be used. Since their introduction to the human-computer interaction design community, their use within interfaces has become a staple. But, despite work to understand how affordances make an interface's available actions transparent, few empirical studies have examined the cognitive origins of this interaction type. Therefore, we explored the impact of cognitive load on affordance-based interactions. Participants were asked to perform a series of affordance-based interactions while under different types of working memory load (no load, verbal, spatial, and central executive). Affordance-based interactions were consistently slowed under central executive load, but never when under verbal load. We conclude that affordance-based interactions do require cognitive resources, but resource costs may only manifest under heavy load. With this knowledge, designers may be able to better predict when an affordance will (or will not) act as if it is resource free. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Intuitive interactions are supported by users' implicit and explicit learning experiences. But, determining user knowledge can be difficult. With many options available for eliciting that knowledge, we tested the effectiveness of two methods--performance and reflection. Users were presented with simple interactions that had varying levels of intuitiveness (affordance, convention, bias). They were asked to perform the interaction or to describe how the interaction should be designed. These methods of knowledge elicitation produced inconsistent results; sometimes they produced the same result (affordance-based interactions), sometimes the opposite (convention-based interactions). Furthermore, when both methods were used, results obtained from the second measure were often contaminated by completion of the first measure. Carryover effects were present regardless of which measure was completed first. These results indicate that the method used to elicit knowledge should be selected based on the type of interaction that is being investigated and multiple measures should be used with caution. [ABSTRACT FROM AUTHOR]