Much has been written about theory and practice in the law, and the tension between practitioners and theorists. Judges do not cite theoretical articles often; they rarely "apply" theories to particular cases. These arguments are not revisited. Instead the Essay explores the working and interaction of theory and practice, practitioners and theorists. The Essay starts with a story about solving a legal issue using our intellectual tools - theory, practice, and their progenies: experience and "gut." Next the Essay elaborates on the nature of theory, practice, experience and "gut." The third part of the Essay discusses theories that are helpful to practitioners and those that are less helpful. The Essay concludes that practitioners theorize, and theorists practice. They use these intellectual tools differently because the goals and orientations of theorists and practitioners, and the constraints under which they act, differ. Theory, practice, experience and "gut" help us think, remember, decide and create. They complement each other like the two sides of the same coin: distinct but inseparable.

Of Theory and Practice

https://hal.archives-ouvertes.fr/hal-00907787/document

Special Section on Touching the 3rd Dimension: A survey of 3D object selection techniques for virtual environments

Issues such as hand and tracker jitter negatively affect user performance with the ray-casting selection technique in 3D environments. This makes it difficult for users to perform tasks that require them to select objects that have a small visible area, since small targets require high levels of precision. We introduce an approach to address this issue that uses progressive refinement of the set of selectable objects to reduce the required precision of the task. We present a design space of progressive refinement techniques and an exemplar technique called Sphere-casting refined by QUAD-menu (SQUAD). We explore the tradeoffs between progressive refinement and immediate selection techniques in an evaluation comparing SQUAD to ray-casting. Both an analytical evaluation based on a distal pointing model and an empirical evaluation demonstrate that progressive refinement selection can be better than immediate selection. SQUAD was much more accurate than ray-casting, and SQUAD was faster than ray-casting with small targets and less cluttered environments.

Rapid and accurate 3D selection by progressive refinement

1983: The first CHI called CHI - computers just processed data and Human-Computer Interaction (HCI) just supported users in their work tasks.Twenty years on, broadband servers and mobile devices now outnumber desktop office machines. With them come joy, persuasion, outrage, delight, faith, campaigns, satire, fun, learning, identity, communities, and passion. Now, increasingly, we interact to be, not just to do. Interaction no longer just changes things, it changes people. HCI is headed for New Horizons.CHI 2003 recognised this sea of change in HCI and addressed all forms of interactive digital communication, with a focus on three special areas: mass communication and interaction, e-learning, and emotion. Many presentations addressed these special areas. Still, CHI 2003 has not abandoned established HCI for New Horizons! Everything you'd expect to find in a CHI conference is still here.These Conference Proceedings contain the papers accepted for presentation at CHI 2003. Competition was fierce. 470 submissions were received, and 75 were accepted. Many of these accepted papers address the challenge of supportive effective and enjoyable communication via interactive digital media.A CD containing the extended abstracts for short talks, demonstrations, design and usability in practice papers, special interest group descriptions, interactive posters, student posters and doctoral consortiumpresentations accompanies these proceedings. Video figures and demonstrations are provided on an additional DVD. These complete the record of CHI 2003 as the meeting place for an inclusive community, The CHI conference is the annual gathering of the world's HCI community. There is something for everyone. Students, researchers, professionals, and educators are spoiled for choice.

CHI '03 Extended Abstracts on Human Factors in Computing Systems

Despite the functional impact of upper limb dysfunction in multiple sclerosis (MS), effects of intensive exercise programs and specifically robot-supported training have been rarely investigated in persons with advanced MS. To investigate the effects of additional robot-supported upper limb training in persons with MS compared to conventional treatment only. Seventeen persons with MS (pwMS) (median Expanded Disability Status Scale of 8, range 3.5–8.5) were included in a pilot RCT comparing the effects of additional robot-supported training to conventional treatment only. Additional training consisted of 3 weekly sessions of 30 min interacting with the HapticMaster robot within an individualised virtual learning environment (I-TRAVLE). Clinical measures at body function (Hand grip strength, Motricity Index, Fugl-Meyer) and activity (Action Research Arm test, Motor Activity Log) level were administered before and after an intervention period of 8 weeks. The intervention group were also evaluated on robot-mediated movement tasks in three dimensions, providing active range of motion, movement duration and speed and hand-path ratio as indication of movement efficiency in the spatial domain. Non-parametric statistics were applied. PwMS commented favourably on the robot-supported virtual learning environment and reported functional training effects in daily life. Movement tasks in three dimensions, measured with the robot, were performed in less time and for the transporting and reaching movement tasks more efficiently. There were however no significant changes for any clinical measure in neither intervention nor control group although observational analyses of the included cases indicated large improvements on the Fugl-Meyer in persons with more marked upper limb dysfunction. Robot-supported training lead to more efficient movement execution which was however, on group level, not reflected by significant changes on standard clinical tests. Persons with more marked upper limb dysfunction may benefit most from additional robot-supported training, but larger studies are needed. This trial is registered within the registry Clinical Trials GOV (
 NCT02257606
 ).

https://link.springer.com/content/pdf/10.1186%2Fs12984-015-0043-3.pdf

Robot-supported upper limb training in a virtual learning environment : a pilot randomized controlled trial in persons with MS

When interacting in a virtual environment, users are confronted with a number of interaction techniques. These interaction techniques may complement each other, but in some circumstances can be used interchangeably. Because of this situation, it is difficult for the user to determine which interaction technique to use. Furthermore, the use of multimodal feedback, such as haptics and sound, has proven beneficial for some, but not all, users. This complicates the development of such a virtual environment, as designers are not sure about the implications of the addition of interaction techniques and multimodal feedback. A promising approach for solving this problem lies in the use of adaptation and personalization. By incorporating knowledge of a user's preferences and habits, the user interface should adapt to the current context of use. This could mean that only a subset of all possible interaction techniques is presented to the user. Alternatively, the interaction techniques themselves could be adapted, e.g. by changing the sensitivity or the nature of the feedback. In this paper, we propose a conceptual framework for realizing adaptive personalized interaction in virtual environments. We also discuss how to establish, verify and apply a user model, which forms the first and important step in implementing the proposed conceptual framework. This study results in general and individual user models, which are then verified to benefit users interacting in virtual environments. Furthermore, we conduct an investigation to examine how users react to a specific type of adaptation in virtual environments (i.e. switching between interaction techniques). When an adaptation is integrated in a virtual environment, users positively respond to this adaptation as their performance significantly improve and their level of frustration decrease.

/pdf/adaptation-in-virtual-environments-conceptual-framework-and-387mkl1dcp.pdf

Adaptation in virtual environments: conceptual framework and user models

Designers and developers of virtual environments have to consider that providing adaptation in virtual environments is important to comply with users' different characteristics. Due to the many possibilities of adaptation that a designer can think of, it is necessary to support the integration of adaptation in the application in a rapid and practical way. We propose to achieve this by adopting the VR-DeMo model-based user interface design (MBUID) process which supports context. In this paper, we strive to integrate adaptation in virtual environments using a context-aware design process and present a validation of this approach with two case studies, namely supporting the adaptation of switching between interaction techniques and adapting the interaction technique itself. These case studies learned us that adaptation can be easily realized using our context-aware model-based design process.

/pdf/facilitating-adaptation-in-virtual-environments-using-a-4amj7f40du.pdf

Facilitating adaptation in virtual environments using a context-aware model-based design process

Leveraging interactive systems by integrating adaptivity is considered as an important key to accommodate user diversity and enhance user interaction A virtual environment is a highly interactive system which involves users performing complex tasks using diverse 3D interaction techniques Adaptivity has not been investigated thoroughly in the context of virtual environments This PhD research is concerned with embedding intelligence to enhance user interaction in virtual environments (i.e providing adaptive personalized 3D interaction techniques).

/pdf/enhancing-user-interaction-in-virtual-environments-through-41qljxbdpp.pdf

Enhancing user interaction in virtual environments through adaptive personalized 3d interaction techniques

The 2010 IEEE Symposium on 3D User Interfaces ran the symposium's first 3DUI Grand Prize, a contest for innovative, practical solutions to classic 3DUI problems. The authors describe the rationale for the first contest and give an analysis of all submissions. Each category's winners also discuss their solutions.

/pdf/3dui-2010-contest-grand-prize-winners-15b23f9ilp.pdf

3DUI 2010 Contest Grand Prize Winners

The complex nature of virtual environments customarily hinders users to interact in a natural, intuitive and optimal way. Different user characteristics are hardly taken into account when designing 3D user interfaces for virtual environments. We envision that user interaction in virtual environments can be enhanced by integrating adaptation and personalization into 3D user interfaces. Through our research, we aim to provide adaptive and personalized 3D user interfaces for enhancing user interaction in virtual environments. The establishment of a user model becomes an important first step to facilitate adaptation and personalization to the user. In order to partly construct the user model, we carried out an experiment on 3D target acquisition task with four user groups (differing in experience level and gender). In this paper, we present a general user model that will enable first-time users to benefit instantly from adaptation and personalization in virtual environments.

Johanna Renny Octavia

Papers

Adaptation in virtual environments: conceptual framework and user models

Facilitating adaptation in virtual environments using a context-aware model-based design process

Enhancing user interaction in virtual environments through adaptive personalized 3d interaction techniques

3DUI 2010 Contest Grand Prize Winners

Investigating the Possibility of Adaptation and Personalization in Virtual Environments