Année 2019, numéro spécial
Power wheelchairs remain an efficient means of regaining mobility for many people around the world. Unfortunately, some are not able to use power wheelchairs because of difficulties using a standard joystick. People with neuromuscular diseases who experience a loss in muscular strength find it difficult to use of a joystick. In this paper, we explore steering power wheelchairs using a tactile interface on a smartphone. Eleven users with neuromuscular diseases tried this type of steering in free learning sessions. Four among them were able to take part in an experiment where we evaluated their kinematic performance between the use of the tactile steering interface and the joystick. The paper presents data and observations from both sessions and tries to detect tendencies and draw hypotheses that can guide further and in-depth clinical testing of the tactile steering for wheelchair users suffering from neuromuscular diseases. Overall, the user performance with the tablet was close or the same as their performance with the joystick. In addition, the users reported a lesser level of physical demand of the tactile steering over the joystick
With the massive spread of Internet use, the accessibility of user interfaces (UI) is an ever more pressing need. Much work has been developed on this subject in order to define generic or situational accessibility recommendations and to propose tools for user interface adaptation. However, difficulties remain, particularly related to the complexity of possible contexts of use, such as the multiplicity of characteristics of the context of use, the imprecision of the values assigned to these characteristics and the combination of multiple adaptation rules. This article shows how a dynamic adaptation engine based on fuzzy logic can be used to implement accessibility recommendations. We show how this approach makes it possible to overcome these difficulties through fuzzy logic with the capacity to manage combinatorial rules, making it possible to take into account potentially complex contexts of use. This approach is illustrated with a concrete example.
Although ubiquitous data analysis is a promising approach, analyzing data in spreadsheets on tablets is a tedious task due to the limited size of the display and tactile vocabulary. In this article, we present the design and evaluation of new interaction techniques based on the combination of a tablet containing the data and a smartphone used as a mediator between the user and the tablet. To do this, we propose to use stacking gestures, i. e. to place a smartphone on top of a tablet. Stacking is an inexpensive, easy to implement, efficient and effective way to improve the analysis of data on tablets, increasing the vocabulary and broadening the display surface by using smartphones that are always available. We first explore stacking-based solutions to delimit the possible interaction vocabulary and present the manufacture of a conductive shell for smartphones. Then, we propose new techniques based on stacking to perform data analysis of a spreadsheet, i.e. the creation of pivot tables and their manipulation. We evaluate our stacking techniques against the tactile interactions provided by current mobile spreadsheet applications. Our studies reveal that some of our interaction techniques are 30% faster than touch to create pivot tables.
Raycasting is the most common target pointing technique in virtual reality environments. However, performance on small and distant targets is impacted by the accuracy of the pointing device and the user's motor skills. Current pointing facilitation techniques are currently only applied in the context of the virtual hand, i.e. for targets within reach. We propose enhancements to Raycasting : filtering the ray, and adding a controllable cursor on the ray to select the nearest target. We describe a series of studies for the design of the visual feedforward, filtering technique, as well as a comparative study between different 3D pointing techniques. Our results show that highlighting the nearest target is one of the most efficient visual feedforward technique. We also show that filtering the ray reduces error rate in a drastic way. Finally we show the benefits of RayCursor compared to Raycasting and another technique from the literature.