Level of detail (LOD) is widely used to control visual feedback in interactive applications. LOD control is typically based on perception at threshold -- the conditions in which a stimulus first becomes perceivable. Yet most LOD manipulations are quite perceivable and occur well above threshold. Moreover, research shows that supra-threshold perception differs drastically from perception at threshold. In that case, should supra-threshold LOD control also differ from LOD control at threshold?In two experiments, we examine supra-threshold LOD control in the visual periphery and find that indeed, it should differ drastically from LOD control at threshold. Specifically, we find that LOD must support a task-dependent level of reliable perceptibility. Above that level, perceptibility of LOD control manipulations should be minimized, and detail contrast is a better predictor of perceptibility than detail size. Below that level, perceptibility must be maximized, and LOD should be improved as eccentricity rises or contrast drops. This directly contradicts prevailing threshold-based LOD control schemes, and strongly suggests a reexamination of LOD control for foveal display.

This paper describes an experimental investigation into the relationship of delay to user performance in 3D object placement. In the first experiment, 10 participants performed a placement task as delay and placement difficulty varied. Results were analyzed with statistical analyses of variance. Placement errors and times rose as delay and difficulty increased. An interaction indicated that controlling delay is particularly important when placement is already difficult. In vehicle control tasks, previewing forecasts required input, and is a useful way of compensating for delay. The second experiment examined the relationship of previewing to delay and difficulty in placement. With regard to delay and difficulty, the 15 participants replicated the first experiment's results. Previewing reduced placement times directly, and mitigated the effects of delay and difficulty. A three-way interaction indicated that when previewing is used, more delay can be tolerated even in difficult placement tasks.

We investigated performance in a complex, dynamic decision-making task. Individual judgment performance in a command and control environment was modeled as linear combinations of environmental cue values using a lens model approach. Examination of the judgment models indicated that participants had similar judgment policies, while correlational and error analyzes indicated that performance differences were due to participants' abilities to execute judgment strategies rather than their knowledge of the task environment. The research demonstrated how the lens model approach can be extended to account for dynamic aspects of decision making in complex environments, through the use of individual, time dependent environmental models for each participant. Additionally, the research showed that a lens model approach is useful for characterizing factors in individual performance in complex judgment tasks. Empirically, this research suggests that training on task knowledge should be supplemented by training which focuses on the consistent execution of judgment strategies.

322 subjects participated in an experimental study to investigate the effects of tactile, olfactory, audio and visual sensory cues on a participant's sense of presence in a virtual environment and on their memory for the environment and the objects in that environment. Results strongly indicate that increasing the modalities of sensory input in a virtual environment can increase both the sense of presence and memory for objects in the environment. In particular, the addition of tactile, olfactory and auditory cues to a virtual environment increased the user's sense of presence and memory of the environment. Surprisingly, increasing the level of visual detail did not result in an increase in the user's sense of presence or memory of the environment.

Article Free Access Share on Making computers easier for older adults to use: area cursors and sticky icons Authors: Aileen Worden Psychology, Georgia Institute of Technology, Atlanta, Georgia Psychology, Georgia Institute of Technology, Atlanta, GeorgiaView Profile , Nef Walker Psychology, Georgia Institute of Technology, Atlanta, Georgia Psychology, Georgia Institute of Technology, Atlanta, GeorgiaView Profile , Krishna Bharat GVR, Georgia Institute of Technology, Atlanta, Georgia GVR, Georgia Institute of Technology, Atlanta, GeorgiaView Profile , Scott Hudson GVR, Georgia Institute of Technology, Atlanta, Georgia GVR, Georgia Institute of Technology, Atlanta, GeorgiaView Profile Authors Info & Claims CHI '97: Proceedings of the ACM SIGCHI Conference on Human factors in computing systemsMarch 1997 Pages 266–271https://doi.org/10.1145/258549.258724Published:27 March 1997Publication History 193citation3,057DownloadsMetricsTotal Citations193Total Downloads3,057Last 12 Months119Last 6 weeks16 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Previous work has demonstrated the utility of reductions in the level of detail (LOD) in the periphery of head-tracked, large field of view displays. This paper provides a psychophysically based model, centered around an eye/head movement tradeoff, that explains the effectiveness of peripheral degradation and suggests how peripherally degraded displays should be designed. An experiment evaluating the effect on search performance of the shape and area of the high detail central area (inset) in peripherally degraded displays was performed, results indicated that inset shape is not a significant factor in performance. Inset area, however, was significant: performance with displays subtending at least 30 degrees of horizontal and vertical angle was not significantly different from performance with an undegraded display. These results agreed with the proposed model.

Two user studies were performed to evaluate the effect of level-of-detail (LOD) degradation in the periphery of head-mounted displays on visual search performance. In the first study, spatial detail was degraded by reducing resolution. In the second study, detail was degraded in the color domain by using grayscale in the periphery. In each study, 10 subjects were given a complex search task that required users to indicate whether or not a target object was present among distracters. Subjects used several different displays varying in the amount of detail presented. Frame rate, object location, subject input method, and order of display use were all controlled. The primary dependent measures were search time on correctly performed trials and the percentage of all trials correctly performed. Results indicated that peripheral LOD degradation can be used to reduce color or spatial visual complexity by almost half in some search tasks with out significantly reducing performance.

We present a careful evaluation of the sensory characteristics of the CyberGlove model CG1801 whole-hand input device. In particular, we conducted an experimental study that investigated the level of sensitivity of the sensors, their performance in recognizing angles, and factors that affected accuracy of recognition of flexion measurements. Among our results, we show that hand size differences among the subjects of the study did not have a statistical effect on the accuracy of the device. We also analyzed the effect of different software calibration approaches on accuracy of the sensors.

Two experiments are reported that examine the effects of menu organization and command naming on performance within and across computer command menus. The work on performance within menus extends prior work on information retrieval (IR) menus to computer command menus. We found that selection of computer commands conforms to the same laws that govern selection of IR categories and object names, with alphabetic organization leading to shorter search times in early trials when users knew the names of the commands. When users did not know the exact names of the commands, the functional organization led to shorter search times. More importantly, we found that the knowledge of the functional organization transferred from one application menu to another, thereby reducing search time in the menu of the second application.

HCI research at Georgia Tech is found in three cooperating groups: the Engineering Psychology and Experimental Psychology Programs in the School of Psychology, the Center for Human-Machine Systems Research in the School of Industrial and Systems Engineering, and the interdisciplinary Graphics, Visualization and Usability (GVU) Center. We cooperate via cross-listed courses, having students in one area take a minor in another area, collaborative research projects, serving on Ph. D. committees, joint colloquia and brown bag lunches, and joint appointments. The GVU Center (housed in the College of Computing) and Cognitive Science Program (sponsored by Psychology, Industrial and Systems Engineering, and the College of Computing) involves a number of the same faculty, further enhancing our collaborations.

This study examined the effects of visualization ability on search time in databases with different hierarchical structures. It was designed to determine whether manipulation of the hierarchical structures of information could accommodate the needs of low‐visualization ability users. The task consisted of finding specific “target” files in each of the four different data structures that varied in depth of organization. The study found the expected effects of organizational structure and visualization ability on retrieval time from the database. It did not find any evidence of an interaction between the two variables on performance. The results suggest that individual differences in performance are the result of differences in perceptual speed and that altering the structure of the information in a database is not an effective way to accommodate to low‐visualization ability users.

This paper reports on an experiment that investigated factors which effect selection time from walking menus and bar or pull-down menus. The primary focus was on the use of impenetrable borders and on expanding target areas on the two menus types. The results show that both factors can be used to facilitate menu selection, with the use of borders being most beneficial. In addition, the results suggest that even on large monitors, the time required to access items from a bar menu is less than that required for the best walking menu.

An exploratory effort to classify visual representations into homogeneous clusters is discussed. The authors collected hierarchical sorting data from twelve subjects. Five principal groups of visual representations emerged from a cluster analysis of sorting data: graphs and tables, maps, diagrams, networks, and icons. Two dimensions appear to distinguish these clusters: the amount of spatial information and cognitive processing effort. The authors discuss visual information processing issues relevant to the research, methodology and data analyses used to develop the classification system, results of the empirical study, and possible directions for future research.>

We formulated a set of rules for producing key-commands that are alternatives for activating commands with a mouse from a menu. Because software is getting increasingly complex, it was important that the rules cover a wide variety of commands. The rules combined verb-modifier-object order and mnemonic abbreviations for the words in each slot. Our keybindings were shown not only to cover a wide set, but to be far easier to learn than EMACs (a common keybinding set) and a more robust form with respect to negative interference from prior and post-learning of another set.