The Paper presents multimedia system for accessible distant education which consists of multimedia browser accessible for visually impaired people and content distribution streaming server integrated with e-learning management system, which allow interactive online access to storage materials in DAISY 3 (ANSI/NISO Z39.86 2005 Specifications for the Digital Talking Book) format. The developed DaisyReader offers new functionality for interactive multimodal (visual and voice) presentation of structural information like: tables, lists and math formulas. DaisyReader supports new MathML Modular Extensions (2007) of Daisy standard.
Visually impaired people have limited access to traditional printed educational materials. Nowadays more and more publishers, schools and universities offer digital educational materials and e-learning services. Computers with assistive technologies give impaired people potential independent access to digital information. However accessibility of digital content strongly depends on information format, presentation and its structure.
Screen readers, screen magnifiers and multimedia browsers allow impaired users easy access to traditional text book’s content. A lot of educational materials present multimedia content: text, pictures, audio, video, graphs, charts and other structural information like math formulas, especially technical and scientific materials. Accessibility of complex structural information for visually impaired people is limited and requires designing alternative interactive multimodal presentation (visual voice and tactile).
We present new multimedia eBook format (DAISY 3.0 ANSI/NISO Z39.86-2005) developed by Daisy Consortium www.daisy.org. Daisy books present book content in multimode form including text, audio and graphics. Readers can easily navigate in logical book structure by: chapters, headings, pages, paragraphs and sentences. Daisy books can be played using hardware or software players. Currently world wide there are about 130000 book titles in Daisy format.
We present developed interactive system for accessible distant education which main components are shown in Figure 1.
SERVER
Learning management system
Multimedia server WWW Server License Server Text searching
Server
CLIENT
WWW
browser
Inrteractive
multimedia
browser
The goal of our research is accessible interactive multimodal (visual, voice and tactile) presentation of
educational materials, especially scientific content which often consists of graphs, charts and other
structural information like math formulas. Interface of e-learning management system has been
designed with the special attention to requirements of blind and low vision students and allows direct
access to educational materials by internet services
The accessibility of e-learning materials is one of the main problem in ICT system. In our approach we propose design course materials in DAISY standard.
Currently available Daisy players allow to read multimedia Daisy books only from CD/DVD discs or local computer hard discs. Books recorded on CD/DVD's are collected personally or ordered by mail in the library. Some libraries offer digital books by Internet. This method requires full book contents download over the Internet before start reading it. Books in Daisy format range from several to hundreds of megabytes in size. Downloading large amounts of data makes this approach to books’ distribution both difficult and time consuming. Access to information contained in multiple books is very difficult and multiple books information searching is practically impossible.
In our continuous research and development of the multimedia e-learning system we have designed
and developed new multimedia Daisy books browser
Similar as in printed books readers can add bookmarks with text, audio notes and exchange
bookmarks list each other
Previous research focused on conversion from math formulas represented in TeX to math Braille
notation. Daisy Consortium approved Specification for a Digital Talking Book Modular Extension for
Mathematics in 23 February, 2007
During our research we defined the rules of conversion from MathML content representation to voice
representation in Polish language. We compared it to the previous work of
Daisy book containing basic and complex series of math expressions with comments was prepared in order to test implemented algorithms for interactive voice browsing. We proposed testing methodology for this experiment. Firstly, examples were grouped by used math operators, structure and complexity. Next, we prepared questionnaires for teachers, which helped collecting information about the way how math formulas were browsed, tester math experience and disability level. Moreover, some parts of tests were recorded for later additional analysis of questionnaires. There were two groups of test participants: pupils and university students, both blind or low vision. Each of the groups consisted of people who were beginning learning math and those who were more advanced in this discipline. Before test had been conducted, teachers demonstrated how to browse math with DaisyReader. During the test, participants examined series of basic and complex equations using interactive voice browsing commands of DaisyReader. Math formulas were presented in groups of the same category and in mixed ones in order to evaluate novice users understanding level. Math teachers together with testers gathered notes about problems with understanding math expressions and suggestions how to improve proposed reading functions.
We modified our approach to rules of voice reading math formulas on the basis of experiment results and extended proposed vocabulary for describing expressions. Moreover, we implemented audio signalisation of expression structure during examination of formulas. After the suggested changes tests were conducted for the second time. Both of the test results showed that complex formulas need to be examined more carefully and a few times to be understood correctly. Low-vision students in comparison to blind students tended to better recognise structure of complex formulas, because of accessing multimodal (simultaneous visual and voice) presentation of information. Results of tests showed us that visually impaired people using DaisyReader can understand most of presented math formulas. In future we plan to conduct more tests on larger scale together with schools and universities. We are currently working on adding Math Braille formulas presentation in order to raise up level of math understanding.
Our interactive multimedia Daisy books browser works together with multimedia Helix Universal
server. Multimedia Helix server is integrated with the e-learning management system
Additional browser mechanisms preload book fragments and allow to present book contents without interruptions. Files are accessed in parallel with audio multimedia stream. Loaded xml files (containing book text) are buffered in Daisy browser memory which allows for smooth navigation. The user can search for information in the document before the document is loaded. The text search server implements this function. After the search request is processed and information about found text is passed back to browser. This information allows Daisy browser to playback book contents from any fragment that meets the search criteria.
Selected multimedia streaming server (Helix Universal Server) works in a multiprocessor environment and allows for simultaneous data transmission and multi user service. During our work we tested the system’s scalability with a dual processor Pentium server running Linux operating system. Scalability tests were conducted using special developed client and test coordination server applications with client applications up to 100. The purpose of those tests was to evaluate quality of transmitted audio streams and book content data. Client applications collected statistics of received and lost packets. They also offered recording from audio streams, which were evaluated by groups of people. Tests
Our research is the result of national project Multimedia Presentation of structural information accessible for all and European FP6 IST project: European Accessible Information Network – www.euain.org. In our research interactive voice and visual presentation of math formulas have been developed based on collaboration with math teachers, impaired pupils and students. During our study we propose several voice reading methods for basic and advanced maths formulae and examples. Alternative presentation of different math formulas needs to develop new rules of conversion from MathML to voice representation. Reading of math formulas is different from language to language. We focus on Polish and English languages. Our tests of DaisyReader in schools shown that this application can be successful aid in learning math. Developed e-learning platform will be used in education of impaired people in Poland.