Modeless Pointing with Low-Precision Wrist Movements

Part 1: Long and Short Papers (Continued)International audienceWrist movements are physically constrained and take place within a small range around the hand's rest position. We explore pointing techniques that deal with the physical constraints of the wrist and extend the range of its input without making use of explicit mode-switching mechanisms. Taking into account elastic properties of the human joints, we investigate designs based on rate control. In addition to pure rate control, we examine a hybrid technique that combines position and rate-control and a technique that applies non-uniform position-control mappings. Our experimental results suggest that rate control is particularly effective under low-precision input and long target distances. Hybrid and non-uniform position-control mappings, on the other hand, result in higher precision and become more effective as input precision increases

Designing Disambiguation Techniques for Pointing in the Physical World

International audienceSeveral ways for selecting physical objects exist, including touching and pointing at them. Allowing the user to interact at a distance by pointing at physical objects can be challenging when the environment contains a large number of interactive physical objects, possibly occluded by other everyday items. Previous pointing techniques highlighted the need for disambiguation techniques. Addressing this challenge, this paper contributes a design space that organizes along groups and axes a set of options for designers to relevantly (1) describe, (2) classify, and (3) design disambiguation techniques. First, we have not found techniques in the literature yet that our design space could not describe. Second, all the techniques show a different path along the axes of our design space. Third, it allows defining of several new paths/solutions that have not yet been explored. We illustrate this generative power with the example of such a designed technique, Physical Pointing Roll (P2Roll)

Configuration Tool and Experimental Platform for Pointing Devices

In user studies of human-computer interaction, experiments on new devices and techniques are often made on experiment software, which is developed separately for each device and technique. A systematic experimental platform, capable of running experiments on a number of technologies, would facilitate the design and implementation of such experiments. To do this, a configurable framework was created to allow relative pointing and absolute pointing input to be enhanced with adaptive pointing and smoothed pointing techniques. This thesis discusses both the internals of the framework as well as how a platform is developed based on the framework. Additionally, two calibration modules were designed to transform the relative pointing input to absolute pointing and obtain the necessary parameters which will be applied in smoothed pointing. As a part of the deployment, the experiment module was made to provide a platform which allowed the enhanced pointing experience to be evaluated and generated proper output according to the results of the experiment task. One key achievement presented in this thesis is that the relative pointing devices are integrable with adaptive pointing and smoothed pointing which support for absolute pointing devices in general. Another key result presented in this thesis is that the configurable framework based experimental platform provides proper functions which meet the demands of professional pointing evaluation. ACM Computing Classification System (CCS): I.4.1 [Digitization and Image Capture]: Camera calibration, I.4.3 [Enhancement]: Smoothing, I.4.8 [Scene Analysis]: Trackin

Mobile Pointing Task in the Physical World: Balancing Focus and Performance while Disambiguating

International audienceWe address the problem of mobile distal selection of physical objects when pointing at them in augmented environments. We focus on the disambiguation step needed when several objects are selected with a rough pointing gesture. A usual disambiguation technique forces the users to switch their focus from the physical world to a list displayed on a handheld device's screen. In this paper, we explore the balance between change of users' focus and performance. We present two novel interaction techniques allowing the users to maintain their focus in the physical world. Both use a cycling mechanism, respectively performed with a wrist rolling gesture for P2Roll or with a finger sliding gesture for P2Slide. A user experiment showed that keeping users' focus in the physical world outperforms techniques that require the users to switch their focus to a digital representation distant from the physical objects, when disambiguating up to 8 objects

A Human Motor Behavior Model for Direct Pointing at a Distance

Models of human motor behavior are well known as an aid in the design of user interfaces (UIs). Most current models apply primarily to desktop interaction, but with the development of non-desktop UIs, new types of motor behaviors need to be modeled. Direct Pointing at a Distance is such a motor behavior. A model of direct pointing at a distance would be particularly useful in the comparison of different interaction techniques, because the performance of such techniques is highly dependent on user strategy, making controlled studies difficult to perform. Inspired by Fitts’ law, we studied four possible models and concluded that movement time for a direct pointing task is best described as a function of the angular amplitude of movement and the angular size of the target. Contrary to Fitts’ law, our model shows that the angular size has a much larger effect on movement time than the angular amplitude and that the growth in the difficulty of the tasks is quadratic, rather then linear. We estimated the model’s parameters experimentally with a correlation coefficient of 96%

Control theoretic models of pointing

This article presents an empirical comparison of four models from manual control theory on their ability to model targeting behaviour by human users using a mouse: McRuer’s Crossover, Costello’s Surge, second-order lag (2OL), and the Bang-bang model. Such dynamic models are generative, estimating not only movement time, but also pointer position, velocity, and acceleration on a moment-to-moment basis. We describe an experimental framework for acquiring pointing actions and automatically fitting the parameters of mathematical models to the empirical data. We present the use of time-series, phase space, and Hooke plot visualisations of the experimental data, to gain insight into human pointing dynamics. We find that the identified control models can generate a range of dynamic behaviours that captures aspects of human pointing behaviour to varying degrees. Conditions with a low index of difficulty (ID) showed poorer fit because their unconstrained nature leads naturally to more behavioural variability. We report on characteristics of human surge behaviour (the initial, ballistic sub-movement) in pointing, as well as differences in a number of controller performance measures, including overshoot, settling time, peak time, and rise time. We describe trade-offs among the models. We conclude that control theory offers a promising complement to Fitts’ law based approaches in HCI, with models providing representations and predictions of human pointing dynamics, which can improve our understanding of pointing and inform design

Large Display Interaction via Multiple Acceleration Curves and Multifinger Pointer Control

Large high-resolution displays combine high pixel density with ample physical dimensions. The combination of these factors creates a multiscale workspace where interactive targeting of on-screen objects requires both high speed for distant targets and high accuracy for small targets. Modern operating systems support implicit dynamic control-display gain adjustment (i.e., a pointer acceleration curve) that helps to maintain both speed and accuracy. However, large high-resolution displays require a broader range of control-display gains than a single acceleration curve can usably enable. Some interaction techniques attempt to solve the problem by utilizing multiple explicit modes of interaction, where different modes provide different levels of pointer precision. Here, we investigate the alternative hypothesis of using a single mode of interaction for continuous pointing that enables both (1) standard implicit granularity control via an acceleration curve and (2) explicit switching between multiple acceleration curves in an efficient and dynamic way. We evaluate a sample solution that augments standard touchpad accelerated pointer manipulation with multitouch capability, where the choice of acceleration curve dynamically changes depending on the number of fingers in contact with the touchpad. Specifically, users can dynamically switch among three different acceleration curves by using one, two, or three fingers on the touchpad