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Non Visual Surfing on the Internet:

the BrailleSurf browser

Dominique Burger & Djamel Hadjadj

INSERM U483 - Inova

9, Quai Saint-Bernard, 75252 Paris cedex 05

Abstract. This paper describes an non visual Internet browser that was developed to provide an access to HTML pages easier than most of the current access solution for the Internet are. Multimodal interaction methods have been devised to accelerate the reading and navigation process via a few basic browsing functions. For each function, optimal combinations of speech, Braille and adapted screen display have been sought among which the user can choose according to his/her own preferences. Tests made in schools and universities with nearly 30 handicapped users clearly demonstrated that this interface can make HTML documents quite accessible after a very short training for non expert users of computers.

Keywords: Internet, Web, Blind, Low Vision, Browser

1. Introduction

It is always difficult for visually handicapped people to gain access to the sources of written information. This seems to be one of the main barriers they encounter the modern society for their social and professional integration. This is particularly true in education, where written material are essential. The recent advent and drastic growth of the Internet is completely revising this problem and seems to be able to provide efficient solutions.

The BrailleNet project was created in September 1996 in order to promote the use of Internet in the education of the visually handicapped in France. It includes user organisations, schools and universities, research laboratories and industrial companies [1]. Its main achievements, during the first year of the project, were the creation of an educational network, the creation of a useful Web Site for students and the development of Internet access solutions.

The targeted user in this project are student who very often do present a low level of computer literacy and/or knowledge of assistive technology. Most of them are at the primary or secondary schools. Early in 1997, observations of the access solutions used in the different schools affiliated to the BrailleNet network were made completed by discussions with teachers. This preliminary study revealed that the use of a standard browser plus a Windows access software created a barrier whose consequences were a rather long learning time and an heavy mental load on the user. To say it short, the visually handicapped user has to understand and master via non visual peripherals (Braille or speech) :

Thus, it was hypothesised that an browsing solution that would concentrate on a basic functions needed to read an HTML page, navigate within an hypertext document and perform the few associated operations, like recording bookmarks or saving pages, would be a stimulating tool in the BrailleNet project.

The possibility to use the pbWebSpeak browser, developed by Productivity Works, was examined [2]. But as this browser was mainly designed for speech output this solution was rejected. Thus, as INSERM had an experience in developing multimodal interfaces it was decided to develop an HTML interface whose main objective was to provide an easy and intuitive reading functionality for non expert users of computer systems, based on the combination of Braille, speech and large display on the screen. It was also expected that a specific browser would standardise the pedagogical approach across schools, in spite of the big variety of the access technologies used. Finally, the solution proposed should also be compatible with the various Braille/Speech solutions encountered (8 main manufacturers sharing the market in France).

This paper presents the software solutions proposed to reach these objectives and the results obtained. It also briefly discusses it in comparison with other solutions that have emerged recently.

2. A Simple Model

HTML has been derived from SGML with the scope of creating a simple, general and flexible frame for the description of an hypertext and hypermedia documents. An hypertext is based on two main components: nodes and links. In an hyperdocument a node is a page, while a link creates paths between pages. Thus two types of functions were considered in designing BrailleSurf :

2.1 Page reading

HTML makes possible to describe a page as a succession of basic elements whose features are well defined. This is very coherent with the use of speech or Braille since both of them are suited to a linear presentation of data. Two basic commands may be used to skim over an HTML page :

The most meaningful elements which can be found in a page are : Texts, Headings, Links, Forms, Tables, and Images.

Thus, specific mechanisms were designed for reading or interacting with each type of those elements. For instance : Reading a text; Activating a link; Getting feedback concerning data input; Navigating within a table; Accessing the textual description of an image. These mechanisms vary according to the communication mode and/or the peripheral used, for example a Braille bar makes possible to read a text by blocks of a limited number of characters (20,40 or 80), in contrary to speech output which can read a text by sentence, by word, or even spell it.

2.2 Hypertext navigation

Two basic functions are associated to a link : to activate it - which means going from one page to another – and to go back to the initial page. If the system is able to keep the memory of the path followed, two functions can be used to go back or forward several steps. Functions are also provided to go to a given URL address, and to create and retrieve bookmarks.

3. A Multimodal interface

Efforts in designing and developing BrailleSurf have been made for an intuitive access to these few basic functions. The method was to combine tactile, auditory and visual modalities. The combinations can be modulated according to the preferences of the user.

Some examples of how this can be given :

3.1 Feedback about transient events is given on the auditory channel

3.2 The possibilities of a channel can be extended

3.3 Several channels are used redundantly to reinforce messages

3.4 The user has the possibility to easily switch from one communication mode to another

Moreover, general interface design principles have been followed [3].

4. Implementation

BrailleSurf is built with four main software modules [Figure 1]: A Customisation Interface allows the user to choose options according to the hardware configuration and to his/her preferences. The use of several Braille bars and speech synthesisers available on the European Market is possible. A Downloader module sends requests to Web server using the HTTP protocol. It can also load HTML files from a hard disk, a diskette or a CD-ROM, as well. An HTML Filter module processes the source documents and prepares them before their presentation in Braille, speech or large print display. Adapted documents are then passed to the User Interface through which the user can read the document and interact with it. BrailleSurf was developed in the Windows 95 and Windows NT environment using the engineering concepts proposed by the ActiveX technology (COM and OLE Automation). The programming environment was Visual C++ 4.2 and its extensions (MFC. SDK, APL,...). [4]

Figure 1 : Integration scheme into Microsoft ActiveX

5. Results

Nearly 15 educational settings participating in the BrailleNet project were provided with a beta version of the BrailleSurf browser for evaluation. About 30 students from the primary school to the university used it regularly during their school. Their comments and suggestions were taken into account in the development process. This experiment clearly demonstrated that the design principles adopted in the interface designing makes HTML hypertexts quite accessible. For most of the users, the training duration was very short (not exceeding one hour) to understand the interaction principles and the browsing functionality. This easy adaptation was also observed with university students being non expert in computers as well as with children at the primary school level.

The BrailleSurf software can now be and can be dowloaded free from : the Web Site of INSERM - Inova [5].

Figure 2 : home page of BrailleNet presented by Internet Explorer and by BrailleSurf.

6. Conclusion

The possibility to have access to structured and standardised documents over the Internet and the availability of powerful software components make possible to create applications and human computer interfaces that fit in with the needs of the visually handicapped users. This opens new avenues to overcome the barriers resulting from the generalisation of graphical user interfaces.

Since we have started this project, other browsers have been designed to match the needs of handicapped users. This confirms the interest of researchers for specific solutions aiming at customising interfaces for targeted groups. For instance the AVANTI browser has been designed in the frame of an EC project to embed Design for All principles. An application has been demonstrated for people with motor disabilities [6]. The Sigtuna Browsing Software provides another example. This speaking browser can be downloaded as a freeware from a web site [7].

As it combines Braille, speech and large display, BrailleSurf remains an original attempt, whose success among users goes growing as it provides a cross assistive technology platform.

Nevertheless, it should be emphasised however that techniques used to make browsing easier at the interface level - as done with BrailleSurf - cannot overcome all the difficulties encountered by the visually handicapped on the Web. These difficulties are well known and largely discussed elsewhere in this conference. They are related to the use of graphics and pictures without any textual comment, to the immoderate use of Java scripts to convey information or to dirty structured documents. Unfortunately too many sites still seems ignore the Access For All design principles [8].

For this reason, early, it appeared necessary early in the BrailleNet project to create an experimental Web Site in order to guide users toward accessible sources of data available on the Web. This site is proved to be an useful complement to BrailleSurf and also to any other browsing tool for the blind [1].

7. Acknowledgements

This project has been granted by the Fédération des Aveugles et Handicapés Visuels de France.

8. References

[1] BrailleNet,

[2] Productivity Works,

[3] Burger D., Improved Access for the visually Handicapped : New Prospects and principals, In: IEEE transactions on rehab Engin., 1994, pp. 111-118

[4] Hadjadj D., Agro R. & Burger D., Customising HTML by filtering: techniques for making Internet accessible to the visually handicapped, 3rd ERCIM Workshop User Interface for All, 1997, pp. 219-224.


[6] C. Stephanidis, A. Paramythis, M. Sfyrakis, A. Stergiou, N. Maou, A. Leventis, G. Paparoulis, C. Karagiannidis, "Adaptable and Adaptive User Interfaces for Disabled Users in AVANTI Project", 5th International Conference on Intelligence in Services and Networks (IS&N '98), "Technology for Ubiquitous Telecommunications Services", Antwerp, Belgium, 25-28 May 1998.

[7] Sigtuna Browsing Software,

[8] The Web and Disabled People,