Applying Fitts’ Law to Gesture Based Computer Interactions

abstract: As gesture interfaces become more main-stream, it is increasingly important to investigate the behavioral characteristics of these interactions – particularly in three-dimensional (3D) space. In this study, Fitts’ method was extended to such input technologies, and the applicability of Fitts’ law to gesture-based interactions was examined. The experiment included three gesture-based input devices that utilize different techniques to capture user movement, and compared them to conventional input technologies like touchscreen and mouse. Participants completed a target-acquisition test and were instructed to move a cursor from a home location to a spherical target as quickly and accurately as possible. Three distances and three target sizes were tested six times in a randomized order for all input devices. A total of 81 participants completed all tasks. Movement time, error rate, and throughput were calculated for each input technology. Results showed that the mean movement time was highly correlated with the target's index of difficulty for all devices, providing evidence that Fitts’ law can be extended and applied to gesture-based devices. Throughputs were found to be significantly lower for the gesture-based devices compared to mouse and touchscreen, and as the index of difficulty increased, the movement time increased significantly more for these gesture technologies. Error counts were statistically higher for all gesture-based input technologies compared to mouse. In addition, error counts for all inputs were highly correlated with target width, but little impact was shown by movement distance. Overall, the findings suggest that gesture-based devices can be characterized by Fitts’ law in a similar fashion to conventional 1D or 2D devices

Combined Head Gestures for Improved User Interaction

Fine-grained gestures such as eye gaze, facial expressions, etc., can be useful as input mechanisms for smart devices. However, single gesture inputs such as eye gaze are inefficient, and it is difficult to perform complex operations with such inputs. This disclosure describes techniques to fuse multiple head gestures, e.g., head, eye, mouth, or eyebrow movement, to provide superior user interaction. Head gestures are classified as analog (e.g., eye movements, which provide continuous input) or binary (e.g., frowns, which indicate one-time operation). An analog gesture is fused with multiple binary gestures to improve efficiency. For example, to move an object, the user selects the object by looking and frowning at it; moves the object using eye gaze; and frowns again to set it in position. Different facial expressions can be flexibly assigned to accommodate varied user abilities and preferences

The human factors of computer input using a mouse device

This thesis investigates how people select items from a computer display using the mouse input device. The term computer mouse refers to a class of input devices which share certain features, but these may have different characteristics which influence the ways in which people use the device. Although task completion time is one of the most commonly used performance measures for input device evaluation, there is no consensus as to its definition. Furthermore most mouse studies fail to provide adequate assurances regarding its correct measurement.Therefore precise and accurate timing software were developed which permitted the recording of movement data which by means of automated analysis yielded the device movements made. Input system gain, an important task parameter, has been poorly defined and misconceptualized in most previous studies. The issue of gain has been clarified and investigated within this thesis. Movement characteristics varied between users and within users, even for the same task conditions. The variables of target size, movement amplitude, and experience exerted significant effects on performance. Subjects consistently undershot the target area. This may be a consequence of the particular task demands. Although task completion times indicated that mouse performance had stabilized after 132 trials the movement traces, even of very experienced users, indicated that there was still considerable room for improvement in performance, as indicated by the proportion of poorly made movements. The mouse input device was suitable for older novice device users, but they took longer to complete the experimental trials. Given the diversity and inconsistency of device movements, even for the same task conditions, caution is urged when interpreting averaged grouped data. Performance was found to be sensitive to; task conditions, device implementations, and experience in ways which are problematic for the theoretical descriptions of device movement, and limit the generalizability of such findings within this thesis

Energy Flux Characterisation of Atmospheric Pressure Plasma Spray Torches with Passive Thermal Probes

Passive thermal probes were applied on two different plasma spraying devices to gain a detailed understanding of the energy flux towards the substrate under atmospheric pressure. The challenge of very high thermal load was solved by using an advanced time-resolved measuring and evaluation technique. The combination with a controlled movement of the jets allowed to obtain insightful radial profiles. The energy flux to the substrate changes linearly to the electrical input power. When adding diatomic gases (H2/N2) to the gas mixture the energy flux increases significantly, suggesting a more efficient energy transport. For increasing the axial distance, the energy flux shows a quadratic reduction. The obtained radial profiles are exemplarily utilized to show the inhomogeneous effect of powder injection on the energy flux distribution

Comparison of input devices in an ISEE direct timbre manipulation task

The representation and manipulation of sound within multimedia systems is an important and currently under-researched area. The paper gives an overview of the authors' work on the direct manipulation of audio information, and describes a solution based upon the navigation of four-dimensional scaled timbre spaces. Three hardware input devices were experimentally evaluated for use in a timbre space navigation task: the Apple Standard Mouse, Gravis Advanced Mousestick II joystick (absolute and relative) and the Nintendo Power Glove. Results show that the usability of these devices significantly affected the efficacy of the system, and that conventional low-cost, low-dimensional devices provided better performance than the low-cost, multidimensional dataglove

Interactive form creation: exploring the creation and manipulation of free form through the use of interactive multiple input interface

Most current CAD systems support only the two most common input devices: a mouse and a keyboard that impose a limit to the degree of interaction that a user can have with the system. However, it is not uncommon for users to work together on the same computer during a collaborative task. Beside that, people tend to use both hands to manipulate 3D objects; one hand is used to orient the object while the other hand is used to perform some operation on the object. The same things could be applied to computer modelling in the conceptual phase of the design process. A designer can rotate and position an object with one hand, and manipulate the shape [deform it] with the other hand. Accordingly, the 3D object can be easily and intuitively changed through interactive manipulation of both hands.The research investigates the manipulation and creation of free form geometries through the use of interactive interfaces with multiple input devices. First the creation of the 3D model will be discussed; several different types of models will be illustrated. Furthermore, different tools that allow the user to control the 3D model interactively will be presented. Three experiments were conducted using different interactive interfaces; two bi-manual techniques were compared with the conventional one-handed approach. Finally it will be demonstrated that the use of new and multiple input devices can offer many opportunities for form creation. The problem is that few, if any, systems make it easy for the user or the programmer to use new input devices

Switch access to technology - A comprehensive Guide.

When most of us use a computer we use the standard interface of a keyboard and mouse. However, what do you do if you cannot use a keyboard or mouse? A number of alternative access systems exist, for example: alternative keyboards, tracker balls, touchscreens, head pointers etc. But for some people these devices are also an impossibility, and this is where switches 'kick in'. The main subject of this document is the switch user. For completeness we have include a brief mention of other input devices, which may be grouped together as 'alternative access systems'.We aim to: - Encourage developers to include switch access into their products - Standardise practice and terminology. This document explains some of the issues involved for people with severe physical difficulties who access computers and other electronic devices with switches. It details the ways in which switch users interact with computer programs and other technology designed to be directly accessible to them. The document includes some precise definitions of terms. It also attempts to survey the whole range of issues associated with switch use. As such it should be useful to professionals working or entering the field, those software developers considering switch users for the first time and also for those already developing in this area

Is movement better? Comparing sedentary and motion-based game controls for older adults

Providing cognitive and physical stimulation for older adults is critical for their well-being. Video games offer the opportunity of engaging seniors, and research has shown a variety of positive effects of motion-based video games for older adults. However, little is known about the suitability of motion-based game controls for older adults and how their use is affected by age-related changes. In this paper, we present a study evaluating sedentary and motion-based game controls with a focus on differences between younger and older adults. Our results show that older adults can apply motion-based game controls efficiently, and that they enjoy motion-based interaction. We present design implications based on our study, and demonstrate how our findings can be applied both to motion-based game design and to general interaction design for older adults. Copyright held by authors