The project developed at the Faculty of Informatics is motivated by the aim to make programming easier for visually impaired students. The project consist of the following parts:

• Dialog generator of program source – special phonetically based editor of the program sources that can be used to facilitate building of source code and to prevent syntactical bugs.
• Library of procedures for programming of visually impaired people.
• Application of the blind user oriented hypertext system AUDIS to provide a run-time library overview and to provide the information about the correct use of procedures and functions.

The ideas behind the dialog generator of source code can be formulated as follows:

• Control of the system is supported by speech synthesis and recognition.
• Sound information is preferred whenever it is effective. It can be produced in the form of speech input and output, user speech comments and remarks to the source text, audio glances and earcons , environmental sounds etc.
• Source code generation is performed in the form of man-machine dialog fully supported by speech synthesis and recognition.
• The dialog is performed in such a way that it prevents the users from committing syntactical (and to some extents semantical) errors and makes the building of the program simpler.
• The system provides the user with complex information about the actual position in the source code also related to the relevant program blocks.
• The system provides convenient reading (in audio form) and effective editing of program parts.

There are several factors related to declarative paradigm that could be of some interest if we consider visually impaired programmers. We will demonstrate it on Prolog because it is typical, standardized, and widespread representative of logic programming.

Opposite to imperative languages, Prolog program is a composition of the unique type of data structures – terms. The meaning of a Prolog program is more intuitive as the components of the program are logical statements of a given form1.

The consequence for visually impaired users lies in the possibility to avoid treatment for various data structures and control structures, that makes the programming more natural and simple. However, the main difference issues from the style of thinking while programming. Imperative program is a sequence of steps that lead to the solution of a considered problem. In logic programming the computer is provided with author's knowledge about the problem (specification of the problem) in the form of facts and rules, thus enforcing insight of the problem and supporting high-level abstraction.

The knowledge should comprise a model of the problem. Well-designed model of the problem allows the user to ask different questions related to the problem, i.e. single program can give multiple solutions related to the problem.

Another benefits come from the inherited concepts of recursion and backtracking, simple manipulation with dynamic lists, powerful all-solution predicates, nondeterminism and many more. Newly added constraint solving features even allow to write programs just as a specification of the problem.

Dialog generator of the program clauses working on similar principle as in the previous section would be helpful for visually impaired programmers. We assume to analyze the relevant dialogs and to make some experiments.

Head of the Project

Ivan Kopecek

Faculty of Informatics, Botanicka 68a,

60200 Brno, Czech Republic

Team (in alphabetical ordering)

Pavel Gaura , Adriana Jergova, Ivan Kopecek, Ludek Matyska