Evaluating Body Tracking Interaction in Floor Projection Displays with an Elderly Population


The recent development of affordable full body tracking sensors has made this technology accessible to millions of users and gives the opportunity to develop new natural user interfaces. In this work we focused on developing 2 natural user interfaces that could easily be used by an elderly population for interaction with a floor projection display. One interface uses feet positions to control a cursor and feet distance to activate interaction. In the second interface, the cursor is controlled by ray casting the forearm into the projection and interaction is activated by hand pose. The interfaces were tested by 19 elderly participants in a point-and-click and a drag-and-drop task using a between-subjects experimental design. The usability and perceived workload for each interface was assessed as well as performance indicators. Results show a clear preference by the participants for the feet controlled interface and also marginal better performance for this method.

Due to the increasing number of elderly in developed countries and the specific needs of this population we tried to get an insight of the desirability of different modes of controlling interaction in interactive floors. A medium which, by being easily scaled, can mitigate the visual perception deficits associated with old age, and can promote physical activity. Thus, in this work, two methods of interacting with virtual elements projected on the floor were developed and tested for differences in their usability, perceived workload and performance ratings by an elderly population. The interfaces consisted on either controlling the cursor with the direct mapping of feet position onto the projection surface or, alternatively, by mapping the cursor position to the participant’s ray-casted forearm on the surface. These interfaces were tested on two different tasks, one mimicking a point-and-click interaction, the other a drag-and-drop. Although the NUI research field is extensive there is a lack of studies that approach the floor projected interfaces and studies with the elderly are even rarer. This study gives a successful insight into the preferred modes of interaction for this elder population. Contrary to our initial guess, the results showed that from the two proposed methods the “feet” interface was superior in all the domains measured. It was shown that this method was perceived as more usable in both the tasks tested and at least less demanding in terms of workload for the drag-and-drop task. In terms of performance a marginal advantaged was shown also for the “feet” method. This insight delivered by the results will help in the development of systems aiming at providing full body NUI for floor projection displays such as in mobile robots. 

Reference:

Afonso Gonçalves and Mónica Cameirão (2016). Evaluating Body Tracking Interaction in Floor Projection Displays with an Elderly Population. Presented at the PhyCS 2016 - 3rd International Conference on Physiological Computing Syst, Lisbon. (Download) (Cite)




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