Michelle Sublette

Green Expectations The Story of a Customizable Lighting Control Panel Designed to Reduce Energy Use

Environmental control and sustainability have become increasingly important in the design of workspaces. Lighting systems in particular have undergone many changes through the incorporation of computer- integrated control panels working in tandem with occupancy and light sensors. Such control panels can allow for increased perceived environmental control which has been shown to improve job satisfaction and productivity (Kroner, 1992; O’Neil, 2004). However, these controls must be designed effectively according to a number of principles regarding interaction design, including good stimulus-response compatibility and adherence to population stereotypes. The purpose of this study is to evaluate the usability of one such control panel being used in a smart, green building, and to see how the shortcomings in the design may force users to default to the most familiar setting, which may not be the most energy efficient.

A First Look at Identifying Strategies People Use in Making Predictions about Task Demand

As shopping from online retailers continues to increase, designers need to be aware of the strategies consumers are using to predict the ease-of-use of products based on appearance. The following study investigates the influence of task type (stimulus-response compatibility task, target-acquisition task, perceptual-search task) on these strategies. The results suggest that for abstract tasks (motor and search), participants are relying on elements in or interactions with the actual stimulus such as the predicted time to complete the task and the number of items in the stimulus. However for tasks that are more concrete (using a stove), participants rely on their past experiences and familiarity with the task to predict task difficulty.

Do Operators Take Advantage of A Secondary, Global-Perspective Display when Performing a Simulated Laparoscopic Search Task?

Multi-display surgical environments have the potential to increase performance and efficiency while decreasing errors and workload. However as more and more information is required for complex task execution and decision making, we must continually assess how the information is presented and whether we are helping or hindering surgeons by providing more content. Most laparoscopic surgeries are performed utilizing a single, two-dimensional (2-D) display. In the current experiment, we compared display usage, subjective workload, and workload measured via eye-tracking data to determine the effectiveness of an additional three-dimensional (3-D) display for a simulated surgical search task. We found that while participants did use the additional display in less demanding conditions (e.g., with fewer search targets), they did not use the supplemental display in conditions with greater demands, and they did not receive a substantial benefit from the presence of the supplemental display in either condition. Both increased saccades per target and increased perceived workload via the NASA-TLX provided support that more workload was experienced in conditions with more targets. And while participants did perceive decreased workload for more targets when the 3-D display was available, eye-tracking metrics were not consistent with participants’ subjective workload estimates. Since subjective workload ratings may be influenced by expectancies for benefits for the additional display, future research should attempt to understand this workload dissociation as well as breakdowns in the usage of supplemental displays as a function of task difficulty.

Environmental Control Issues in a New Energy-Efficient Building

The availability of adjustable lighting controls, with options other than “on” and “off,” have been associated with increased energy savings. In the present study, we describe the way customizable, networked lighting controls are actually used in a recently built research facility that received a formal designation for sustainable design (LEED Gold). In addition to usage patterns, we explored occupants’ knowledge of control operation as well as the expectancies of nonoccupants. We also identified a variety of features that, if redesigned in accordance with HF/E principles, might lead to reduced lighting usage.

Further Explorations of the “White Space” Bias in Users’ Anticipation of Task Workload

As more designers allow users to customize the look and feel of interfaces, users will be required to recognize the implications of their choices on their future performance, comfort, and enjoyment. Understanding the limits of people’s predictive capabilities may be an important component in identifying why people choose one product over another based on ease of use or why people have difficulties identifying tasks that can be performed together. The purpose of this study is to further explore users’ biases for utilizing the amount of white space in the stimulus as a predictor of task difficulty, to validate discrepancies between predicted task difficulty and performance outcomes found in previous research and the human factors literature, and to identify task-specific strategies that are used to anticipate task difficulty. The study uses the NASA Task Load Index (NASA-TLX) in prospective difficulty judgments for these three types of tasks: 1) a stimulus-response compatibility task, 2) a target acquisition task and 3) a perceptual search task. In general, participants predicted lower task demand for designs with more intervening white space. For the visual search task, these estimates of demand were consistent with participants’ actual performance reaction times. However, for the stove design and Fitts’ tasks participants rated tasks that were likely to result in more errors as less challenging suggesting that the type of task is an important factor in participants’ abilities to predict relative task difficulty.

The Design of Product Comparison Tables and its Effects on Decision Making

Consumers are constantly presented with new information about new products. The presentation of this information can affect decision making processes by varying the form, organization, and sequence of the information (Kleinmuntz & Schkade, 1993). One organization strategy frequently used in marketing is a product comparison table which allows for side-by-side comparisons to be made. Two decision making heuristics which can occur when using such tables are the “as-if (AI) heuristic,” where all features are treated “as if” they are equal in importance or value, and the other is the “elimination-by-aspect (EBA) heuristic,” where a preferred feature must be present for an alternative to be considered further. One design manipulation that could affect such heuristics when using a table is shading. When applying the Proximity Compatibility Principle (PCP) and theories of visual search, it is easy to see how shading can influence or shape the perceptual acquisition of information and, in turn, affect decision making strategies. This research looked at shading orientation and its effects on decision making during a guided choice task. The study of spontaneous choice is ongoing.

Potential Performance Costs Associated with Large-Format Tiled Displays for Surgical Visualization

Twenty-five participants performed a surgical training task on a large format display created from one projector or by tiling the images from a 4-, or 9-projector array. Utilizing a large-format display consisting of tiled projector images brings the potential benefits of increased display size with the potential threats to performance of inherent visual artifacts. The effect of these artifacts on performance and subjective workload was assessed. Results indicate that while display size did not affect performance on the surgical task, differences in mental workload were observed. Although a global measure of workload indicated that the tiled displays were the least demanding to use, participants reported deploying additional but highly specific cognitive resources when using these same displays. Their resource shifts seemed to involve adjustments to the perceived control gains created by enhanced size and also degraded ability to compare target sizes in the larger display, possibly due to the obscuring effect of tile edges.

Flashy or Functional The Impact of Graphical Content on the Effectiveness of Résumés

Résumés sometimes contain graphical elements, and the use of such “graphical résumés” may be increasing. The purpose of this study was to compare the effect of including different types of graphical elements in a résumé on the most important outcome measure from the perspective of the applicant – the probability of a positive selection decision by the evaluator. There was a reliable preference for a textual résumé when participants asked which design they thought would be most effective. However, there was no reliable effect of résumé design on evaluator’s decisions about the applicant whose qualifications were represented.

The Impact of Aesthetic Design on Bus Shelter Usability

Public transportation is an important tool for any city with the population to support it. According to the American Public Transportation Association (APTA) (2012), between 1995 and 2011, public transportation ridership increased by 34%—a growth rate higher than the 17% increase in U.S. population and higher than the 22% growth in the use of the nation’s highways over the same period. However, even a city with the population to support public transportation will not receive all of its benefits if the implementation is not handled successfully. One requirement for bus transit is that the system be equipped with shelters having minimally the following features: support, visibility, security and information access (Ely, 1998). A field study was conducted to ascertain the impact of these design elements as well as aesthetic pleasantness on users’ perceptions of the shelters. Ultimately, our goal is to implement future results in the creation of a needs-based heuristic framework which will aid designers in the formation of functional bus shelters.

Interval Production as a Secondary Task Workload Measure: Consideration of Primary Task Demands for Interval Selection

Twenty-eight participants performed a surgical training primary task along with a concurrent time estimation (interval production) secondary task. Fourteen participants were given a primary task that varied in motor demand; the other fourteen performed a primary task that varied in cognitive demand. Time estimation is an attractive option as a workload measure due to its low cost and ease of implementation. Currently it is unclear whether the structure of task demands influences the sensitivity of time estimation tasks that use different intervals. The sensitivity of both a short (3 second) and long (21 second) interval were observed in tasks that differed in level of workload. Results indicated that short intervals were more sensitive to changes in motor workload while long intervals displayed more sensitivity to changes in cognitive demand.