This table has four columns, the headings of which are Domain, Example, Technology, and Reference. The Domain column describes the area in which each VE is used. The Example column describes the context in which each VE is used. The Technology column describes the type of technology involved. The Reference column provides the source of information. The links go to the relevant reference in the reference list.
Domain 1: education. Example: science - simulated laboratory experiments. Technology: head mounted display. Reference: Nemire, 1995.
Domain 2: training. Example: mobility skills - familiarisation with route. Technology: head mounted display. Reference: Mowafy & Pollack, 1995.
Domain 3: communication. Example: gesture recognition. Technology: glove input. Reference: Kalawsky, 1993.
Domain 4: rehabilitation. Example: physical therapy - recovery of manual skills. Technology: joystick and/or other interaction devices. Reference: Bowman, 1997.
Domain 5: access to information technology. Example: sensory transposition - transfer visual presentation to tactile. Technology: force feedback display. Reference: Hardwick et al., 1997.
This is a text description of Table 2, Mean perceived size/angle of virtual objects with percent over- and underestimation (data from sighted and blind participants combined). In this description the data for each object type and each object size or angle. The following paragraphs contain useful information for reading this description. The column headings in this table are: Object Type. Actual Size/Angle (cm/degrees). Perceived Size/Angle: Inside presentation. Perceived Size/Angle: Outside presentation.
The columns headed 'Perceived Size/Angle: Inside presentation', and 'Perceived Size/Angle: Outside presentation', are both divided into two sub-columns. These sub-columns are headed: 'Mean and standard deviation (cm/degrees)', and 'Over/Under estimation (Percent of actual)'.
Sizes are centimetres. Angles are degrees. 'Inside' is an abbreviation of inside presentation. 'Outside' is an abbreviation of outside presentation. 'Over / under' is an abbreviation of over or under estimation. Dash (-) indicates no data for that cell.
Cube: Actual Size 1.0. Inside presentation: mean perceived size 1.8; standard deviation 0.40; over / under + 80%. Outside presentation: mean perceived size see Note 1; over / under -.
Cube: Actual Size 1.5. Inside presentation: mean perceived size 1.7; standard deviation 0.30; over / under + 13. Outside presentation: mean perceived size 1.6; standard deviation 0.50; over / under + 7%.
Cube: Actual Size 2.0. Inside presentation: mean perceived size 2.4; standard deviation 0.20; over / under + 20. Outside presentation: mean perceived size 2.0; standard deviation 0.50; over / under 0%.
Cube: Actual Size 2.5. Inside presentation: mean perceived size see Note 2; standard deviation -; over / under + 20. Outside presentation: mean perceived size 2.4; standard deviation 0.20; over / under - 7%.
Sphere: Actual Size 1.5. Inside presentation: mean perceived size 2.1; standard deviation 0.1; over / under + 27. Outside presentation: mean perceived size 1.2; standard deviation 0.40; over / under - 20%.
Sphere: Actual Size 2.0. Inside presentation: mean perceived size 2.3; standard deviation 0.1; over / under +15. Outside presentation: mean perceived size 1.8; standard deviation 0.50; over / under - 10%.
Sphere: Actual Size 2.5. Inside presentation: mean perceived size 2.5; standard deviation 0.1; over / under 0%. Outside presentation: mean perceived size 2.3; standard deviation 0.30; over / under - 8%.
Rotated cube: Actual angle 30 degrees. Inside presentation: mean perceived size -; standard deviation -; over / under -. Outside presentation: mean perceived size 40 degrees; standard deviation 12.0; over / under + 33%.
Rotated cube: Actual angle 50 degrees. Inside presentation: mean perceived size -; standard deviation -; over / under -. Outside presentation: mean perceived size 52 degrees; standard deviation 12.0; over / under + 4%.
Rotated cube: Actual angle 70 degrees. Inside presentation: mean perceived size -; standard deviation -; over / under -. Outside presentation: mean perceived size 45 degrees; standard deviation 18.0; over / under - 36%.
Sheared cube: Actual angle 18 degrees. Inside presentation: mean perceived size 20 degrees; standard deviation 11.0; over / under + 11%. Outside presentation: mean perceived size -; standard deviation -; over / under -.
Sheared cube: Actual angle 41 degrees. Inside presentation: mean perceived size 37 degrees; standard deviation 11.0; over / under - 10%. Outside presentation: mean perceived size -; standard deviation -; over / under -.
Sheared cube: Actual angle 64 degrees. Inside presentation: mean perceived size 59 degrees; standard deviation 9.7; over / under - 8%. Outside presentation: mean perceived size -; standard deviation -; over / under -.
Notes:1. Preliminary investigations showed that a 1 cm edge cube was too difficult for participants to find in the outside presentation, so it was omitted. 2. Preliminary investigations showed that a 2.5 cm edge cube was too big for the virtual space available. Back to table 2
This figure is a line drawing of the device viewed from its front-right. The device has a circular, upright plate at the front (approximately 25 cms wide) that has a round opening at its centre (approximately 10 cms in diameter). The back of the device is formed by another upright plate, which is triangular with each side being 25 cms long. The front and back plates are joined by three horizontal bars which are approximately 30 cms long. A probe protrudes towards the user from the aperture in the front plate. It is the size and shape of a thick pen. The user moves the probe to feel virtual textures and objects. There are three motors between the front and back plates situated at 12 o'clock, 5 o'clock and 7 o'clock. The probe is attached to the three motors. The motors have dual purpose: they monitor the position of the probe and provide the appropriate force feedback onto the probe.
Back to figure 1
This graph contains three lines. It compares the psychophysical functions of 1) electric shock, 2) apparent length and 3) brightness. Along the horizontal x axis is stimulus magnitude and along the vertical y axis is psychological magnitude. The line for electric shock forms a negative exponential curve. This shows that the intensity of perceived shock increases more rapidly than the intensity of the actual voltage. The line for apparent length forms a straight diagonal (positive) line. This shows that perceived length increases at the same rate as the actual length. The line for brightness forms a positive exponential curve. This shows that the intensity of perceived brightness increases less rapidly than the intensity of the actual brightness.
Back to figure 2
Image description:This figure shows a horizontal sinusoidal (regular) wave which represents a cross-section of the textures that were used. A horizontal arrow indicates that the groove width is measured from peak to peak. The groove widths varied from 0.375 mm to 1.5 mm. A vertical arrow indicates that the amplitude (groove depth) was held constant at 0.0625 mm.
Back to figure 3
This figure is in two parts: diagrams A and B. Both diagrams show a box which represents the device, and a user's hand holding the end of the probe. In diagram A, a virtual cube is located at the end of the probe nearest the user's hand. This shows the way in which some people imagine the virtual objects to be between themselves and the front plate of the device, ie. outside of the device. It also shows that this group believe that the near end of the probe is the part that comes into contact with the virtual object. In diagram B a virtual cube is located at the end of the probe furthest from the user's hand. This shows how some people imagine the virtual objects to be between the front and rear plates of the device, ie. inside the device. It also shows that this group believe that it is the far end of the probe that comes into contact with the virtual object.
Back to figure 4
This figure is in two parts: diagrams A and B. Both diagrams contain representations of virtual cubes. There are arrows going around the cubes which illustrate the movement of the probe around the virtual cube. In diagram A the arrows overshoot the end of the sides of the cube and then point back to the adjoining side of the cube. This shows how a new user finds it difficult to control the probe: it slips off into virtual space, and the user then has to regain contact with the cube. In diagram B the arrows do not overshoot the ends of the sides of the cube, but flow smoothly from one side to the next. This shows how, after a few minutes, the user can control the probe so that when moving from one side of the cube to the next the probe remains in contact with the object.
Back to figure 5
This figure shows a cross-section of a cube that is sheared to the right. (This might be described as an ordinary cube that is tilted, with top and bottom surfaces remaining horizontal.) The corners of the sheared cube are therefore not all of the same angle: two diagonally opposite corners are of wider angles than the other two diagonally opposite corners. The figure has two curved arrows in the narrower corners of the sheared cube, but these arrows do not go right into the corner. There are now arrows in the wider corners. This shows how the probe does not have any difficulty in moving into the wider corners, but it cannot get into the narrower corners, so it tends to skim over them. This can give the impression that these corners are not angled but curved, which can distort the perception of the shape of the object. In the figure the sheared sides of the cube are jagged. This shows that these sides do not feel as smooth as the other two sides.
Back to figure 6
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