1. An ARCHITECTURE FOR TRANSFORMING GRAPHICAL INTERFACES (1994)
Keith Edwards
Elizabeth Mynatt

2. Keith Edwards & elizabeth mynatt
Undergrad, Masters and
PhD from Georgia Tech in CS.
CS Undergrad from North
Carolina State, Masters and
PhD from Georgia Tech in CS.
Thesis on this work in 95.
Currently, both are professors at Georgia Techs School of Interactive Computing; Prior to this, they worked at Xerox PARD and Sun Microsystems

3. Research objective
Develop architecture to transform GUIs into effective and intuitive non-visual interfaces.
Effective small/no screens and visually impaired users
Based on Mercator and X Windows systems

4. Mercator interfaces
Originally designed to provide non-graphical interface to GUI applications for blind users.
Represented different parts of the page with different auditory icons (filtears) e.g. text field sounds like a typewriter, non editable text sounds like a printer; toggle button sounds like chain pull light switch.
Information is arranged in a hierarchical tree structure, and navigation is done using keyboard arrow buttons.

5. X windows systems
Open, cross-platform, client/server system for managing a windowed graphical user interface in a distributed network.
Client-server relationship is reversed - remote computers contain applications that make client requests for display management services in each PC or workstation.
Primarily used in networks of interconnected mainframes, minicomputers, and workstations.

6. Their design goals
Gather enough information to support object based interaction, and be widely applicable.
Guarantee complete knowledge of application’s GUI
Support control for applications GUI and non-visual interfaces
Separate between application operations and syntactic grammar of user input

7. X client/server + Mercator architecture
Several implementation options
Modify all client applications,
“Pseudoserver” between X Server and X Client which understands all server low-level protocols, or
Modify application libraries to communicate with external agent/relink applications. Applications built with new libraries are accessible (changes to Xt, and Xlib). Benefit of a listener to monitor for widgets, pop ups etc. that allows dynamic content presentation
System was later called UltraSonix to differentiate from Mercator

8. Old vs new software architecture

9. Input and output processing
All output is through user interface rules – speech, non-speech and tactile.

10. Treeview implementation – zhang et al. (2012)
Architecture
Webpage Adaptation
Lai, Jianwei, Judith Odili, Isil Yakut Kilic, Dongsong Zhang, and Lina Zhou. "PRECMAS: A Personalized, Cloud-based Integrative Approach to Mobile Web Adaptation." (2015).

11. Treeview implementation – zhang et al. (2012)

12. Apple Voiceover

13. Discussion questions
For those of you with experience in designing or evaluating user interfaces for blind users, how has the implementation and architecture evolved in the last 20 years?
In your opinion, are there any benefits of having both the client and server sit on the same local machine, compared to the client/remote server architecture that is popular nowadays?
Who should make changes to allow accessibility? Users (e.g. Treeview), device manufacturers (e.g VoiceOver) or developers (e.g. Mercator)?