1. A Graph Description Language for Blind Programmers
Dale Parson, Genevieve Smith,
Andrew Wernicki - Kutztown University
PACISE 2017, Edinboro University of PA

2. The Problem
Our graduate course in advanced object-oriented analysis and design makes heavy use of Unified Modeling Language (UML) diagrams.
Our blind student author (Genevieve Smith) needs ways to read and create UML diagrams.
Tactile diagrams of textbook illustrations take too long to internalize and are cumbersome to create.
One diagram can span multiple pages.
She can use the JAWS text reader to capture and debug code with amazing speed!
Our approach is novel in using the waveform appearance of Parallel Coordinates plots to provide the basis for audio time-domain waveforms.

3. Solution: Make a Graph Description Language
UML diagrams are mostly boxes and other graphical containers with visual links, tagged with text.
Use { paired curly braces } to delimit containers.
Use UML keywords for most of the text.
Borrow Java keywords, such as “implements” or “extends”, for textual counterparts to graphics.
Invent keywords only when absolutely necessary. Make them short and descriptive.
Use a Python-based parser generator PLY.
Our approach is novel in using the waveform appearance of Parallel Coordinates plots to provide the basis for audio time-domain waveforms.

4. A Visual UML Class Diagram

5. Abbreviated Textual Class Diagram
class Customer { // Indentation is optional. It slows reading. name [1] ; address [0..1] ; getCreditRange() : String ; } class CorporateCustomer extends Customer { contactName ; creditRating ; creditLimit ; billForMonth(Integer); remind(); } [*]uses[0..1] "salesrep" Employee ;
Genevieve reads figure and discusses using JAWS on it.

6. Diagram generated from text for communication with colleagues

7. A Visual UML Sequence Diagram

8. Abbreviated Textual Sequence Diagram
object anOrder : Order {} object anOrderLine : OrderLine {} object aProduct : Product {} object aCustomer : Customer {} ? calls anOrder.calculatePrice() ; anOrder.calculatePrice() calls anOrderLine.getQuantity() ; anOrder.calculatePrice() calls anOrderLine.getProduct() ; anOrderLine.getProduct() returns aProduct to anOrder.calculatePrice() ;
Genevieve reads figure 4.1 at and discusses using JAWS on it.

9. Pitfalls and UML Extensions
Avoid visual symbols such as “->”, “<-”, “<->”, and “--”. JAWS reads them as punctuation.
We invented keywords new keywords “uses”, “usedby”, “useboth”, and “usehuh” for these.
Nesting curly braces and Java keywords “package”, “static”, “implements”, “extends”, and others are known to most programmers.
Other diagram types require more keywords.
Genevieve takes over usability discussion starting here.

10. Usability We settled on keywords that work with JAWS.
In-line comments and brevity work well.
Coding experience minimizes learning load.
Blind developers can create and read UML diagrams independently.
No need for sighted assistant in the workflow.
No need for long waits for tactile diagrams.
Indentation is optional; it slows reading.

11. Additional Usability
Using JAWS is time-effective and cost-effective for developers who already use it.
Typing text is much faster than drawing tactile diagrams.
Some sighted programmers find graph descriptions faster and more intuitive.
There remains the need to build & maintain a mental map for blind developers.
Back end generates indented and un-indented descriptions and visual graphs.

12. Conclusions
Textual UML for analysis of existing designs sped acquisition of design structure and behavior significantly.
Textual UML capture also much faster and more reliable than tactile punches or rubber band and pin boards.
Iterative prototyping identified feature improvements as the course progressed.
Several sighted students preferred this approach.

13. Future work
The round trip between visual and textual graphs is partially complete.
We can generate image files from text graphs.
Available open-source tools are not modular and are more difficult for blind programmers than readers that they already use.
A visual graph editor that supports tagged graphs, and text-to-graph conversion.
What we already have works well for communicating with colleagues.