Margarita Anastassova

Prototype evaluation and user-needs analysis in the early design of emerging technologies

This paper presents two case studies of prototype evaluation as a tool for user needs elicitation for emerging technologies. In the first user evaluation, a high-fidelity virtual reality prototype is used. In the second one, a low-fidelity mixed reality prototype is used. Our results show that prototypes may be a powerful a tool for eliciting user-needs, but their potentiality depends on their fidelity. In our studies, users elicit more needs when working with the high-fidelity prototypes. Furthermore, the information collected in this case is richer and more useful for design. We discuss these results as well as some factors that could help stakeholders elicit a greater number of needs for emerging technologies.

What's around me? Multi-actuator haptic feedback on the wrist

We present the design, implementation and evaluation of a novel wrist-based vibrotactile multi-actuator bracelet, based on a coplanar circular configuration of actuators, for the provision of intuitive and informative haptic feedback for navigation tasks. A two-phase evaluation was conducted in order to assess the perception of the vibrotactile feedback provided by the bracelet and in particular, the ability of users to discriminate a range of vibrotactile patterns. First, a pilot study designed to test perception of different kinds of pattern was conducted with the aim of both refining the pattern design and aiding the choice of a discriminable set of patterns. Second, an identification experiment with the previously chosen set of patterns was conducted with the aim of conveying navigational directions and points of interest to the user. Results highlighted the difficulties in identifying the number of activated actuators as well as their position on the wrist, which subsequently had an impact on the pattern recognition. It was found that one-way horizontal and vertical movements were difficult to perceive correctly, however, less specific movements such as circular or alternating lateral movements and rhythm proved to be suitable parameters for the perception of patterns as long as the patterns were not too similar in design.

A vibrotactile wristband to help older pedestrians make safer street-crossing decisions

INTRODUCTION Older pedestrians are overrepresented in fatal accidents. Studies consistently show gap-acceptance difficulties, especially in complex traffic situations such as two-way streets and when vehicles approached rapidly. In this context, the present research was aimed at assessing the effectiveness of a vibrotactile device and study older pedestrians behavior when wearing the wristband designed to help them make safer street-crossing decisions. METHOD Twenty younger-old participants (age 60-69), 20 older-old participants (age 70-80) and 17 younger adults (age 20-45) carried out a street-crossing task in a simulated two-way traffic environment with and without a vibrotactile wristband delivering warning messages. RESULTS The percentage of decisions that led to collisions with approaching cars decreased significantly when participants wore the wristband. Benefits tended to be greater particularly among very old women, with fewer collisions in the far lane and when vehicles approached rapidly when they wore the wristband. But collisions did not fall to zero, and responses that were in accordance with the wristband advice went up to only 51.6% on average, for all participants. The wristband was nevertheless considered useful and easy to use by all participants. Moreover, behavioral intentions to buy and use such a device in the future were greater in both groups of older participants, but not among the younger adults. PRACTICAL APPLICATIONS This haptic device was able to partly compensate for some age-related gap-acceptance difficulties and reduce street-crossing risks for all users. These findings could be fruitfully applied to the design of devices allowing communication between vehicles, infrastructures, and pedestrians.

smiles, kids, happy songs!: how to collect metaphors with older adults

In the context of an ageing society, vibrotactile wearable devices can open up new avenues for assisting older adults in their daily lives. They can provide information and yet free the hands, ears and eyes, which can be crucial to safety. However, designing intuitive informational vibrotactile messages for and with the older adults has seldom been investigated. This paper describes an initial study involving older adults in the design of vibrotactile messages for a pedestrian navigation application. The design is based on metaphors or everyday analogies in an attempt to strengthen the link between the pattern and its associated meaning. The study presents the method to collect these metaphors, focusing on the difficulties encountered with such an abstract task and the steps taken to adapt it to the audience. As a result, a number of metaphors were collected, in line with what matters for older adults (e.g. kids, health).

Exploratory Investigation of Vibration Floor as Potential Collision Warning

This paper investigates the possibility of using the floor of a car as potential locus of vibratory collision warnings. Arrangements of three actuators were used to provide vibrating floor patterns. DC motors with eccentric mass and suspended on leaf springs were fixed longitudinally at the center of a metallic structure. The actuators can be activated independently to provide different haptic patterns with different possible amplitudes and temporal frequency parameters. Continuously activated patterns, provided by the simultaneous activation of the actuators can be suggested for high level urgency collision warning as they are considered to be mostly associated to unpleasant, urgent and intrusive judgments. Low level amplitude patterns can be proposed for the advice collision warning.