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Henry H Emurian - One of the best experts on this subject based on the ideXlab platform.
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analysis of cursor Movements with a mouse
Computers in Human Behavior, 1999Co-Authors: Thomas G Whisenand, Henry H EmurianAbstract:Abstract With a mouse input device, 32 experienced computer users moved a cursor from a starting position to a target, both of which were displayed simultaneously on the computer’s screen. Cursor Movements occurred under conditions of variations in the angle of approach to the target, the target size and shape, the distance to the target, and the nature of the task, drag-drop or point-click. In a fully crossed within-subjects design, all variables studied significantly affected Movement Time. Fitts’ law accounted for 44% or 97% of the variance in Movement Time, depending on the method of analysis. Fitts’ law was not equally effective under all combinations of the variables studied. An analysis of residuals showed that residuals were smaller for a point-click task in comparison to a drag-drop task, and residuals were lowest for the largest target displayed at the shortest distance from the starting position. The application of Fitts’ law to cursor Movements with a mouse should be qualified by noting the conditions under which the Movements were observed.
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effects of angle of approach on cursor Movement with a mouse consideration of fitt s law
Computers in Human Behavior, 1996Co-Authors: Thomas G Whisenand, Henry H EmurianAbstract:Research related to various aspects of human-computer interactions has become increasingly important to the design and implementation of effective interface systems and input devices. As the man-machine interface has become more direct, the analysis and application of models to account for this interaction have received increasing attention by investigators. In that regard, the speed and accuracy of human motor Movements associated with computer input devices have often been modeled by Fitts' law. Most such analyses, however, have not considered the angle of approach as a factor. The present study investigated the interactive effects on Movement Time of the angle of approach, the size of the target, and the distance to the target for the use of a mouse to select icon-like targets presented on a computer's display screen. Angle of approach, target size, and target distance significantly affected Movement Time. Although the global R2 based on a Fitts' law linear model was low in comparison with other studies, an analysis of the residuals showed that the linear model's effectiveness in prediction interacted with the other variables under investigation.
Thomas G Whisenand - One of the best experts on this subject based on the ideXlab platform.
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analysis of cursor Movements with a mouse
Computers in Human Behavior, 1999Co-Authors: Thomas G Whisenand, Henry H EmurianAbstract:Abstract With a mouse input device, 32 experienced computer users moved a cursor from a starting position to a target, both of which were displayed simultaneously on the computer’s screen. Cursor Movements occurred under conditions of variations in the angle of approach to the target, the target size and shape, the distance to the target, and the nature of the task, drag-drop or point-click. In a fully crossed within-subjects design, all variables studied significantly affected Movement Time. Fitts’ law accounted for 44% or 97% of the variance in Movement Time, depending on the method of analysis. Fitts’ law was not equally effective under all combinations of the variables studied. An analysis of residuals showed that residuals were smaller for a point-click task in comparison to a drag-drop task, and residuals were lowest for the largest target displayed at the shortest distance from the starting position. The application of Fitts’ law to cursor Movements with a mouse should be qualified by noting the conditions under which the Movements were observed.
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effects of angle of approach on cursor Movement with a mouse consideration of fitt s law
Computers in Human Behavior, 1996Co-Authors: Thomas G Whisenand, Henry H EmurianAbstract:Research related to various aspects of human-computer interactions has become increasingly important to the design and implementation of effective interface systems and input devices. As the man-machine interface has become more direct, the analysis and application of models to account for this interaction have received increasing attention by investigators. In that regard, the speed and accuracy of human motor Movements associated with computer input devices have often been modeled by Fitts' law. Most such analyses, however, have not considered the angle of approach as a factor. The present study investigated the interactive effects on Movement Time of the angle of approach, the size of the target, and the distance to the target for the use of a mouse to select icon-like targets presented on a computer's display screen. Angle of approach, target size, and target distance significantly affected Movement Time. Although the global R2 based on a Fitts' law linear model was low in comparison with other studies, an analysis of the residuals showed that the linear model's effectiveness in prediction interacted with the other variables under investigation.
Yves Rossetti - One of the best experts on this subject based on the ideXlab platform.
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visual pointing and speed accuracy trade off in schizophrenia
Cognitive Neuropsychiatry, 2000Co-Authors: Mohamed Saoud, Patrick Dumas, Thierry Damato, Jean Dalery, Yann Coello, Nicolas Franck, Yves RossettiAbstract:There is a challenge to understand schizophrenia cognitive deficits in terms of a common unifying hypothesis (i.e., context-processing deficit). We suggest that analysis of a low level of cognition, such as the natural tendency to adapt pointing Movement Time to the task difficulty, could provide the basis for understanding higher level processing, in the sense of context processing. In the present study, three-dimensional visually guided pointing Movements were compared among patients with schizophrenia and healthy control subjects. Seventeen patients with schizophrenia and 13 controls, all right-handed, performed pointing Movements on adversely sized targets displayed on a touch-screen. Results showed that, under this experimental procedure, the speed/accuracy trade-off was respected by the two groups, in that controls and patients achieved a constant level of precision whereas they increased reaction Time and Movement Time when target size decreased. In addition, we provide a measurement of the pointin...
Martin Descarreaux - One of the best experts on this subject based on the ideXlab platform.
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head Movement kinematics during rapid aiming task performance in healthy and neck pain participants the importance of optimal task difficulty
Manual Therapy, 2010Co-Authors: Martin Descarreaux, Steven R Passmore, Vincent CantinAbstract:Abstract Background Head repositioning tasks have been used in different experimental and clinical contexts but have yet to offer insight as to the task performance strategy. The purpose of this study was to explore the kinematics from a head aiming task that encompasses a Fitts' task in neck pain patients and healthy control subjects. Methods Chronic neck pain patients and healthy individuals were compared in a head aiming task. Participants were asked to move their head as quickly, and precisely as possible to a target under 4 different experimental conditions. Dependent variables included Movement Time, Movement Time variability, acceleration phase duration, deceleration phase duration and absolute positioning error. Results The chronic neck pain patients, when compared to healthy participants showed a significant increase in Movement Time and deceleration phase duration for the small target/large Movement amplitude condition. No group difference was observed for Movement Time variability, acceleration phase duration and absolute positioning errors. Conclusions Decreased motor performance was observed in chronic neck pain patients during the most challenging cervical pointing task condition. These results may imply that in order for a performance based outcome measure to yield observable differences conditions that meet or exceed the optimum challenge point of the population tested should be employed.
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repositioning accuracy and Movement parameters in low back pain subjects and healthy control subjects
European Spine Journal, 2005Co-Authors: Martin Descarreaux, J Blouin, Normand TeasdaleAbstract:Study Design: A control group study with repeated measures. Objective: To compare trunk repositioning parameters in chronic low back pain (LBP) and healthy subjects. Summary and background data: Recent evidence suggests that chronic LBP patients exhibit deficits in trunk proprioception and motor control. Trunk repositioning and the various spatio-temporal parameters related to it can be used to evaluate sensori-motor control and Movement strategies. Methods: Fifteen control subjects and 16 chronic LBP subjects participated in this study. Subjects were required to reproduce different trunk position in flexion (15°, 30° and 60°) and extension (15°). In the learning phase preceding each condition, visual feedback was provided. Following these learning trials, subjects were asked to perform ten consecutive trials without any feedback. Movement Time, Movement Time variability and peak velocity were obtained and a temporal symmetry ratio was calculated. Peak angular position variability and absolute error in peak angular position were also calculated to evaluate spatial accuracy. Results: Two subgroups of LBP patients were identified. One subgroup of LBP subjects demonstrated longer Movement Time and smaller peak velocities and symmetry ratios than normal subjects. No group difference was observed for peak angular position variability and absolute error in peak angular position. Conclusion: Chronic LBP patients, when given a sufficient learning period, were able to reproduce trunk position with a spatial accuracy similar to control subjects. Some LBP subjects, however, showed modifications of Movement Time, peak velocity and acceleration parameters. We propose that the presence of persistent chronic pain could induce an alteration or an adaptation in the motor responses of chronic LBP subjects.
Scott I Mackenzie - One of the best experts on this subject based on the ideXlab platform.
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towards a standard for pointing device evaluation perspectives on 27 years of fitts law research in hci
International Journal of Human-computer Studies \ International Journal of Man-machine Studies, 2004Co-Authors: William R Soukoreff, Scott I MackenzieAbstract:This paper makes seven recommendations to HCI researchers wishing to construct Fitts' law models for either Movement Time prediction, or for the comparison of conditions in an experiment. These seven recommendations support (and in some cases supplement) the methods described in the recent ISO 9241-9 standard on the evaluation of pointing devices. In addition to improving the robustness of Fitts' law models, these recommendations (if widely employed) will improve the comparability and consistency of forthcoming publications. Arguments to support these recommendations are presented, as are concise reviews of 24 published Fitts' law models of the mouse, and 9 studies that used the new ISO standard.
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Movement Time prediction in human computer interfaces
Human-Computer Interaction, 1995Co-Authors: Scott I MackenzieAbstract:Abstract The prediction of Movement Time in human-computer interfaces as undertaken using Fitts' law is reviewed. Techniques for model building are summarized and three refinements to improve the theoretical and empirical accuracy of the law are presented. Refinements include (1) the Shannon formulation for the index of task difficulty, (2) new interpretations of “target width'' for two- and three-dimensional tasks, and (3) a technique for normalizing error rates across experimental factors. Finally, a detailed application example is developed showing the potential of Fitts' law to predict and compare the performance of user interfaces before designs are finalized.