Objective:

The goal of this project is to design tactile graphics in a three dimensional graphical format, and prototype the designed models for use by blind children in their learning process. These models are intended to help them learn science, math, geography, and other subjects.

Research on Tactile Graphics:

In early February, we drove to The Maryland School for the Blind to meet with Betsy Burnham, the Director of Instructional Resources at the school, to discuss the Maryland School for the Blind's needs and requirements for new tactile graphics. Our group looked at several tactile graphics that the school already owned. While looking at these pages, Betsy pointed out the good and bad graphic characteristics from a blind student's point of view. It is critical to make a graphic that is about the size of two open hands. This is so the student can feel the entire graphic at one time rather than getting lost and needing to constantly move the hands. Also, it is important to keep the tactile graphic simple. If the graphic is too cluttered, the student will become confused and have trouble picturing it in his head. One thing that helps to relieve the cluttered nature of the graphic while still presenting enough information is to have different textures representing items rather than using Braille to describe the item. Since Braille is rather large, this makes a big difference. In order for the student to understand what each texture or Braille abbreviation means, there is usually an attached key that defines the meaning of each texture and abbreviation. Another way to keep the student from becoming confused or lost on the graphic is to put a header consisting of many Braille dots across the top. If the graphic were to become askew, the student can always find the top by finding the header dots. A final method to keep the graphic from becoming confusing, especially if the graphic is a map, is to add a compass rose at the top right of the graphic. This defines the North, South, East and West directions. This helps the students to also get a feel for how the parts of the map relate to each other.

The most critical thing we learned during our research at The Maryland School for the Blind is the importance of making all Braille dots according to convention. First of all, there are dot configurations for the letters of the alphabet and numbers, but there are also configurations for suffixes, prefixes and other commonly used words. This means that it is important to know the language well before you write in Braille or you could misspell the words. There are strict dimensions for Braille dots. The cells must be dome-shaped and have a height of 0.016 in. The distance between each dot must be 0.090 in and each takes up 0.250 in of horizontal line space. The Braille lines must be spaced 0.400 in apart in the vertical direction. For our project, we converted these values to millimeters to match our other predetermined units.

Topic for Model Chosen:

Our group asked Betsy's opinion on the topic for our tactile graphic. We felt it was important to make a product that was needed in the classroom. Betsy definitely felt that a topographical map of the state of Maryland was most critical at this time. Our group decided that this would be a good topic for our tactile graphic.

Original Proposal (February 23, 1998):

Procedure:
 
Timeline

After deciding upon a topographical map of the state of Maryland for our tactile graphic, the next step was to find a quality topographical map to model through research. We spent hours attempting to find an appropriate map and finally decided up on a topographical map found in Rand McNally's World Atlas. Then, we made an enlarged color copy of the map that was roughly the desired size of the tactile graphic. Next, we outlined the Maryland state boundaries on the colored copy on a piece of paper . This outline was made into a transparency that was crucial in creating our Pro/Engineer state boundaries. We taped the transparency to the SGI monitor, and outlined the state boundaries in Pro/Engineer using sketch and spline commands. Then, we created mountains in the western portion of the state using the tweak command.

We made a sample prototype using the SLA machine, then a thermoform to make sure the plastic would mold properly. Sample Braille dots were added to the prototype to see what height and shape had the appropriate effect. We determined that the river areas in the state were too narrow to distinguish between the land and water. Therefore, some changes to the Pro/Engineer drawings needed to be made.

To distinguish between the land and water, raised bars were added to the river areas. Next, the Braille was translated using the web program, The Braille Wizard. The phrases and abbreviations were added to the map. Also, a header made of many dots in a horizontal line was placed at the top of the tactile graphic to indicate the top of the page. Also, a compass was added to the top right corner of the map. This helps the students to understand the orientation of the map. This completed the Pro/Engineer map drawings.

Next, the key was created. This is critical so abbreviations, textures and features can be defined without taking up precious space on the map. A header line and title was added to the top of the key. Then, a mountain tweak was formed to represent the Appalachian Mountains, a textured block was drawn to represent the outline of the state of Maryland, and raised bars were drawn to represent the water areas. The abbreviations for the Chesapeake Bay (CB) and Atlantic Ocean (AO) were the last two definitions on the key.

Once the drawings for the map and the key were completed, the final prototypes of Maryland and the key were made in the stereolithography machine. Once the epoxy had dried, the right and left halves of the map were glued together. After the glue dried, the state of Maryland was painted with textured paint. Finally, the map and key thermoforms were made and the final thermoform was painted for aesthetic reasons.

Reactions from The Maryland School for the Blind:

On Tuesday, May 12, we drove to The Maryland School for the Blind to show them our final products. Betsy Burnham, the Director of Instructional Resources at the school, was pleased with our work. She said the quality of our work was "excellent". Most importantly, she said our Braille translation was perfect and the map was a nice combination of textures and abbreviations. She felt the map would not be confusing for the students because of its lack of clutter and the use of the key.

Betsy did have a few suggestions for our project. The map thermoform had a slight seam down the center from where the left and right halves of the map were glued together. This can be avoided in the future by creating a tighter seal between the two prototype halves. Also, she suggested placing cardboard beneath the thermoforms to help support the plastic. Since our map was large enough to require the thin plastic, it was slightly flimsy. Finally, the letter "B" in the abbreviation for Chesapeake Bay on the map had sunken slightly. To help keep the letter supported, she suggested putting nail polish on the back side of the letter.

Sample Prototype:

Final Products:

Topography of Maryland (above)

Left Half of Map (above)

Right Half of Map (above)

Mountain Region (above)

River Region (above)

The internet Braille Wizard was invaluable to us for translation purposes.  It has a great interface allowing you to type out what you wish to say and it responds with the correct pattern of Braille.  Go visit and give it a try.

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