Nonvisual Graphics Representation Formats
1. Comparison of Audio, Tactile and mixed Audio-tactile Representations of Maps
Recently completed project:
Exploration of Multi-fingered Access to 2D Spatial Information (D. Parker)
This project was motivated by previous work in our laboratory that provided conflicting results as to whether the use of multiple exploring fingers on vibrotactile maps (with cues provided individually to each finger) could improve performance. This project investigated this question in more detail for different types of navigational maps and for different types of questions (some more spatially involved than others). However, as vibration feedback also consumes a lot of battery power (which presents an issue for portable maps), we also were interested in investigating whether sonified cues would work as effectively as tactile cues. We also look at whether perceptual principles of audio stream segregation can be used to effectively relay information about two exploring fingers. Results suggest that users who are blind or visually impaired perform better and prefer the use of sonified cues. Results also suggest that the use of multiple fingers increases performance, although this is more clear for tactile than for sonified cues. This work is currently being written up.
Current project:
Exploration of Non-visual Maps with A Priori Narrative Summary (H. Nathi, M. Pham, collaboration with N. Giudice, Univ. Maine )
This project was motivated by recent work in our laboratory looking at different methods using one or more exploring finger to understand non-visual maps. In that project, when we had participants who were blind or visually impaired answer questions about the maps we presented them with, we found that they were only able to answer at about a 70% correct level. This suggested to us that the method of presentation was limited. However, as the use of portable, virtual audio-tactile methods have many advantages over physical tactile maps, we are exploring ways to help individuals who are blind or visually impaired better understand the virtual maps.
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2. Representing Perspective in Tactile Diagrams
Completed Project:
Improving the Representation of Perspective in Tactile Diagrams (A.M. Ngyuen)
Perspective is very difficult for individuals who are blind or visually impaired to interpret in tactile diagrams as it requires the information in a perspective diagram to be interpreted globally to determine which lines are perspective lines and which lines indicate shape. This project involved the development of local cues that could be added to a perspective diagram so that 3D information about a location in the diagram can be determined upon immediate contact. This was performed by varying the thickness of the lines/edges in a tactile diagram as a function of depth away from the viewer. We found that blind or visually impaired participants performed better using our new method that included local cues.
Effectiveness of Using Local Cues to Indicate Perspective in Tactile Diagrams for People with Visual Impairments
Nguyen, A.M., Ferro, T.J., Pawluk, D.T.V. (2018)
Journal of Visual Impairment and Blindness, JVIB
Paper (PDF)
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3. The Importance of Texture in Tactile Diagrams
Previous projects:
The Use of Virtual Textures and Multiple Fingers to Enhance the Understanding of Tactile Diagrams (D. Burch)
Using multiple contacts with texture-enhanced graphics
Burch, D., Pawluk, D. (2011)
World Haptics Conference (WHC), 2011 IEEE.
Paper (PDF/HTML)
The Perception of Virtual Textures Through a Haptic Multi-pin Display Device (P. Headley)
Roughness perception of textures on a haptic matrix display
Headley, P.C., Pawluk, D.T.V. (2011)
World Haptics Conference (WHC), 2011 IEEE.
Paper (PDF/HTML)