Emergency Information for People with Visual Impairments:
Evaluation of Five Accessible Formats

Part III

W. Crandall, Ph.D., B. Bentzen, Ph.D., L. Myers, M.Ed., R. Easton, Ph.D.

Smith-Kettlewell Rehabilitation Engineering Research Center
2318 Fillmore Street, San Francisco, CA. 94115

METHODS

Subjects
Sixteen participants were recruited by staff at the Carroll Center for the Blind and through individual referrals. Participants were individually interviewed to obtain information for use in matching groups along a number of characteristics, including age, travel aid (long cane or dog guide), amount of vision (participation was limited to those whose maximum vision was limited to an ability to locate the direction of a light source -- “light projection”), onset of blindness (early blind=before age 6; late blind=age 6 and above), frequency of independent travel, use of tactile signs, use of tactile maps, self-evaluation of travel proficiency (excellent, good, fair, poor), and presence of other disabilities or characteristics which could affect performance on this experiment. (See appendix A for prospective subject interview.) Experimenters made the final participant selection based on potential participants identified by Carroll Center staff and through individual referrals. See Table 1 for the distribution of these characteristics across groups.

Table 1. Distribution of subject characteristics across two groups.

It will be noted that the raised print group has a disproportionate number of those who became blind after the age of 6 as compared with the Braille group. Those who read print before they lose their vision are more familiar with the shapes of letters and, therefore, more likely to read raised print more effectively than those who have never read print.

Within the educational system in the United States, a person who has vision insufficient for reading print at about 18 pt type during the elementary school years is likely to be taught to read Braille as a primary reading medium. Persons who become blind later in life may or may not become proficient Braille readers. Raised print is never taught as a primary reading medium, although most persons who are blind, including those born blind, are taught (or teach themselves) to read raised capital letters. No books are produced in raised print, so there is little opportunity to develop real proficiency in reading raised print. However, for a period of years some individuals who were blind were taught to use a technology for converting print to vibrotactile output, that is, the shapes of print letters are presented to the finger as an array of vibrating pins. This technology, called the Optacon (used extensively in the 1970’s and 1980’s), is no longer commercially available, however two participants in the raised print group were former Optacon users. The three participants, blind before age six, in the raised print group also preferred to read Braille.

It was difficult to locate participants who read raised print who did not also read Braille. Even though five participants in the raised print group were blind after the age six, all preferred to read Braille. Two participants who have been blind less than two years expressed a preference for reading Braille over raised print, and were first placed in the Braille reading group. However, when they began training in use of each format in the experiment, it soon became apparent that they were very inexperienced Braille readers and did not know many of the contractions that are used in Braille; they were then switched to the raised print group.

Materials
The five types of wayfinding information tested were Braille (Brl), raised print (RP), tactile maps (TM), push button audible signs (PB) and the remote infrared audible signs system (RIAS). Both raised print signs in AutoCAD Simplex font, kerning = .9 (shown in full size in Fig. 1, Part 1 and continuing in Fig. 1, Part 2) and tactile maps (shown in full size in Fig. 2), were produced by Steven Landau of Touch Graphics, working in association with Dr. Karen Gourgey at the Computer Center for the Visually Impaired at Baruch College.

An exit sign in Braille and raised print was also produced by S. Landau, and mounted at each doorway to a destination stairwell. Braille Signs were provided by H. Toji & Company working in association with Sharon Toji of Access Communications (See Figs. 3).

Figure 1, Part 2

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Figure 2

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Figure 3

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Push-button audible signs were provided by Andco Signage (See Fig. 4).

Figure 4. A battery operated pushbutton audible sign gave the same verbal directions as those delivered in Braille and raised print.


The remote infrared audible signs system was provided by Talking Signs, Inc. (Crandall,et. al., 1999) (See Fig. 5).

Figures 5a, b. Talking SignsR Receiver (a) and Transmitter (b).


Appendix C lists vendors’ names and addresses.

Four routes to be traveled were on four floors of McGuinn Hall, Boston College; however experimenters systematically guided participants from the end of one route to the beginning of the next by a circuitous route that sometimes included exiting the building and entering again by a different door, and using different stairs. One floor was slightly different than the others, but permitted traveling the same path. This floor was always used second so as to predispose participants to think that the routes could be different, even if they had the impression that all routes were in the same building. Other floors were used in random order. The pattern of hallways on each floor may be conceptualized as being shaped like the number “8”. The travel routes were all the same length (285 feet) and all involved four turns . The travel route may be conceptualized as "S-shaped." Two mirror symmetrical paths were used in the study; one path beginning with left turns and the other path beginning with right turns. (See Fig. 6)

Figure 6. The pattern of hallways on each floor are in the form of the number “8”. Participants began the travel route at the location marked “Start” and navigated through the building’s halls in an S-shaped path to finally arrive at the emergency exit door, marked “End” at the opposite end of the building. This figure represents the layout of one of the two mirror symmetrical paths used in the study. The length of each route (“Start” to “End”) was 285 feet.

Two mirror symmetrical routes. The prototype verbal message describing one "S-shaped" route (Braille, raised print and push button audible sign) was as follows:

Turn right. [from a position facing the information source]
Take the next hall going left.
Take the next hall going left.
Take the next hall going right.
Take the next hall going right.
The double doors to the exit stairway are on the left side of this hall.

Required information such as not to use elevators during emergencies, location of fire alarm initiating station, what the fire alarm sounds and looks like, directions for calling 911 was not included. There are two experimental design reasons for not including the additional information: First, the experimenters were concerned that as this required information would be the same for all modes, participants might not actually read or listen to it in all modes. Therefore only the unique information which was necessary for traveling a route to an exit stairway was provided. Second, including all of this required information in an accessible format such as Braille or raised print would be so verbose that the blind person might never get to the needed information -- the route to the exit stairway, which can be extensive in itself.

The tactile map depicted the spatial layout of the halls which would be encountered in traveling the route. A broken line from a you-are-here symbol to an exit stairway symbol indicated the route. A legend in Braille and raised print illustrated the symbols. The entire floor layout was not shown, because this could have led a participant to take a shorter route to the exit than the one required by the experimental design. (See Fig. 1b)

Equipment for each wayfinding mode except the remote infrared audible signs was mounted on a hallway wall at a height (to centerline) of 60 in. The destination door for each route had an exit sign mounted at the right side, at 60 in. height.

California law requires that illuminated EXIT route signs be located in passageways so that one is always in view. That is, the “next” EXIT route sign must always be visible (within the line of sight). Additionally, EXIT route signs must be placed at a maximum of 100 foot intervals so that they can be seen in smoke-obscured conditions. Remote infrared audible transmitters were affixed to ceiling suspended, illuminated EXIT route signs at choice points and EXIT signs at exit doors. (See Fig. 7)

Figure 7. Talking SignsR Transmitter affixed to visual EXIT sign. Message for this sign is: “For exit, take the next hall going right.”


The following six instructions (constructed from four basic messages) comprise the complete Remote infrared audible signs route description:

For Exit, take the next hall going left.
For Exit, take the next hall going left.
For Exit, take the next hall going right.
To the Exit.
For Exit, take the next hall going right.
Exit.

The information provided by the remote infrared audible signs was qualitatively different than the information provided by the other formats. The route to the exit was not described. Participants were not told which side of the hall to look for the exit nor that the exit was double doors. The messages were therefore of only five types: left turn, right turn, straight ahead, and exit in order to coincide with the visual message displayed on the illuminated EXIT signs (placed at locations required by California fire code).


Procedure
All participants used push button audible signs, remote infrared audible signs, and tactile maps. In addition to these three media, one half of the group also used Braille and the other half of the group also used raised print. Therefore, sixteen participants used remote infrared audible signs, push-button audible signs and tactile maps on three routes, eight participants used Braille on one route and eight other participants used raised print on one route. Each wayfinding system was used an equal number of times with each route. Order of routes and wayfinding systems was counterbalanced within and between groups.
Participants were familiarized with the use of each wayfinding system before any route travel began. Systematic familiarization with all four wayfinding formats took place along two hallways of the test building. Familiarization with Braille, raised print, tactile map or audible push-button consisted of having participants read or listen to a route comprised of three turns and information that the double doors to the exit stairway were to be found on one side or the other of the hallway. The information was mounted on a hallway wall just as it would be for the trials. After participants read the route or listened to the audible push-button information, they were asked to describe it in their own words, using gestures to indicate turn directions and the side of the hall on which the door would be located. The order of familiarization with each format was the same as that for testing for each participant. Following familiarization with use of each of the wayfinding information formats, L. Myers, guided participants to the beginning of the first route. She was in control of all direct experimenter interaction with participants during the route travel experiment, guiding them by circuitous routes from the end of one route to the beginning of the next.

During testing, at the beginning of each route, participants were told what format they would be using and then their preferred hand was placed on the tactile map, Braille, raised print, or push-button. When using remote infrared audible signs, participants were positioned near the location of wall-mounted formats, as with the other formats, facing the sign. As soon as they turned the receiver on, they received the first message. Dependent measures were time to read (or listen to) each message and begin traveling toward the destination, time to travel the route, and restarts. Restarts (a measure which has been used extensively by these investigators in other research on wayfinding), occur when participants decide they are off the route and cannot get back to a familiar location on the route. If participants request a restart, timing was stopped and they are taken back to the beginning of the route. Timing was started anew when participants begin to travel the route again. Only the final route travel time was used in the final computation. Maximum time permitted for traveling the length of the route, regardless of whether this was an initial attempt or a restart, was 10 minutes. The three or four fire doors along each route were always closed during route evaluation, as they would be in a fire emergency.

Immediately following route travel, participants individually completed a brief survey regarding their subjective judgments of and experiences with each of the wayfinding information formats.

Later in the same week, two focus groups were held, with nine participants in one and seven in the other. Both groups had persons who had used Braille for the route travel evaluation and persons who had used raised print. Participants participated in a structured group process, under the leadership of B. Bentzen, providing additional subjective information on the use of different formats to provide emergency egress information.

Included in the process was a consideration of the wording of messages, the spacing between characters for the raised print, and the scale of the tactile map. Several alternatives were provided for comparison (See Figs. 8).

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