The first and most common approach is to create universally accessible resources that meet all the accessibility requirements. The main drawback of this approach is that, typically, resources may be accessible by everyone but optimal for no one [ 13].
The second approach used by a number of educational content providers is to create multiple versions of the resources, customized based on the different needs and expectations of the anticipated individual user. While this solves some of the problems with the first approach, it causes new problems, such as the increased costs that eventually result to poor maintenance of these resources, compared to their default version, eventually, providing learners with disabilities with out-of-date and different versions of the digital content [ 14].
The third approach is to build universally accessible systems, that is, systems that can handle learner-centered configurations of resources and/or tools/applications. This is known as the AccessForAll Approach [ 15]. The AccessForAll Approach requires accurate descriptions of both the learners' preferences and/or needs, as well as of the available resources and/or the tools/applications characteristics. However, early systems implementation suffered by the lack of interoperability considerations (that is, sharing resources, activities, and their underlying training practice between systems was not guaranteed), adding extra barriers to the AccessForAll Approach.
2.2.1 Learner Dimension This dimension includes the expression of the individual learner accessibility preferences and the modeling of those preferences into reusable information records. One way to achieve this is by using the IMS Accessibility for Learner Information Package Specification (IMS AccLIP) [ 16]. IMS AccLIP adds a new element on IMS Learner Information Package (IMS LIP) [ 25] to allow learner <accessibility> preferences to be explicitly defined. Rather than targeting at the implicit description of the learner's disabilities, it allows users to explain explicitly how they interface and use a technology-enhanced training system, with their preferences being grouped into <display>, <control>, and <content> elements [ 16]. This offers a flexible user-controlled process for the definition of the learners' characteristics in relation to the preconditions under which the learner interacts with the system, although it does not handle the conditions and features of the current learning situation, needed to be handled by the context dimension.
2.2.2 Resources Dimension This dimension includes the design of resources that are accessible from a specific target group with given disabilities and their tagging with appropriate metadata. The common way for generating accessible digital resource has been by applying the W3C Web Content Accessibility Guidelines 1.0 and their evolution W3C Web Content Accessibility Guidelines 2.0 [ 18], [ 19]. On the other hand, typically, educational resources are described with the IEEE Learning Object Metadata Standard (IEEE LOM) [ 26], so as to be searched, found, and retrieved through established web-based repositories. However, IEEE LOM does not directly support the description of educational resources in terms of their relevance to accessibility characteristics. Efforts have been made to develop Application Profiles of the IEEE LOM Standard that can be used for tagging educational resources with accessibility relevant information [ 27].
Another way to characterize accessible educational resources with metadata is by using the IMS AccessForAll Metadata Specification (IMS AccMD), which aims to provide with metadata that expresses the resource's ability to match the needs and preferences of a certain learner's IMS AccLIP profile. It is intended to assist with resource discovery and also to provide a way that can support the substitution and augmentation of a resource or a resource component with equivalent or supplementary components as required by the accessibility needs and preferences expressed in a learner's IMS AccLIP profile [ 12]. The main disadvantage of this approach is that it relates the description of resources to the description of the learner's condition characteristics in a rather hard-wired way thus, reducing the interoperability only between systems that adopt both the IMS AccLIP and the IMS AccMD specifications.
2.2.3 Tools/Applications Dimension This dimension includes the definition of tools'/applications' accessibility features in relation to the required assistive technology that the tool/application should support. This process can be based on the use of the IMS Guidelines for Developing Accessible Learning Applications, which include the following design considerations [ 17]:
1. accessible delivery of text, audio, images, and multimedia,
2. developing accessible synchronous and asynchronous communication and collaboration tool,
3. developing testing and evaluation tools, including self-assessment and multiple-choice testing,
4. developing accessible authoring tools, and
5. legal issues for accessible distance learning.
An example of a well-known system that conforms to the IMS Guidelines for Developing Accessible Learning Applications is the ATutor ( http://www.atutor.ca) Open Source Course Management System (CMS), developed by the Adaptive Technology Resource Centre of the University of Toronto. ATutor is an accessible course management system built around the IMS AccessForAll specifications, which aims to allow access to all potential learners, instructors, and administrators, including those with disabilities who may be accessing the system using assistive technologies.
2.2.4 Context Dimension This dimension includes the definition of the conditions and features of the learning situation in hand. Context has been defined by Dey [ 28] as “ any information that can be used to characterize the situation of an entity. An entity is a person, place or object that is considered relevant to the interaction between a user and an application, including the user and applications themselves.”
In relation to learning, context can be described as “ the current situation of a person related to a learning activity” [ 29]. Learning context is an important issue in technology-enhanced training today, especially when adaptations and/or customized support is anticipated. Additionally, learning context can be used for making meaningful and accurate recommendations for learning systems configurations and consequently lead to better learning experiences [ 30], [ 31].
Representation of established training practices in a machine-readable way using international specifications (such as the IEEE LOM [ 26] and the IMS Learning Design [ 32]), so that both digital training resources and e-training courses can be reused and interexchanged between different platforms and systems.
Design of a set of reference e-training strategies, as best practice examples for technology-enhanced training of people with disabilities and represent them in a formal machine readable manner using the IMS Learning Design.
Develop tools for learning design and authoring of educational metadata that implement the state-of-the-art learning technologies specifications and standards appropriately modified to deal with the special requirements of disabled people training.
Development of a web-based repository with accessible e-training resources and courses, as well as generic e-training strategies facilitating their storage, search, and retrieval.
E-Training Content Suppliers, that is, the entity responsible for designing and developing independent e-training resources in the form of “learning objects” [ 33]. For the purpose of our work, a learning object is defined as “ potential reusable digital or nondigital resources or a collection of linked resources that are characterized by metadata, and have been designed and developed for a specific audience, their scope is to achieve one or more specified learning goals and they are used in order to support one or more educational activities which feature specified criteria that measure the achievement of the learning goals that have been defined” [ 34]. The e-training content suppliers need to 1) be able to convert their existing e-training resources and/or create new digital resources that meet accessibility requirements of people with disabilities, and 2) be able to characterize these resources with metadata that are meaningful in relation to the accessibility characteristics of the resources. Thus, the eAccess2Learn Framework provides them with a set of guidelines and the technological means for developing accessible e-training resources and tagging them with appropriate educational metadata.
E-Training Courses Suppliers, that is, the entity responsible for designing e-training courses based on a predefined scenario (course template) that reflects the adopted training approach. For the purposes of our work, an e-training course is defined as: “ a sequence of learning activities conducted entirely through the web, targeting specific educational objects and lasting for 8 to 16 didactical hours in total” [ 35]. Moreover, we adopted the following definition for the concept of an e-training course template: “ an eTraining Course Template can be defined as a pedagogical model for an eTraining course, focused on the sequence of generic learning activities that will support teachers and designers to develop particular kinds of learning experiences, one of the aims of an eTraining Course Template is to enable the features of a successful eTraining course to be applied to other eTraining Courses so these may also promote successful outcomes for learners” [ 36]. Thus, the eAccess2Learn Framework provides the e-training course suppliers with a methodology and the technological means for defining their e-training strategies and for representing them in a common machine understandable format following the IMS Learning Design specification [ 32]. Furthermore, the eAccess2Learn Framework provides them with a set of best practice examples of generic e-training course templates which they can use and modify according to their e-training strategies, and offers them access to a web-based repository of e-training resources (in the form of learning objects characterized with appropriate educational metadata), which can both facilitate them in the design and the development of their e-training courses.
E-Training Services Providers, that is, the entity responsible for designing e-training programs as a synthesis of e-training courses and delivering them to people with disabilities. The eAccess2Learn Framework provides them with access to a repository of e-training courses (represented in the form of IMS Learning Designs) which they can use to search and retrieve e-training courses, so as to integrate them to their course management systems.
3.3.1 eAccess2Learn Learning Design Toolkit for Designing E-Training Course Templates and E-Training Courses This is a software tool that enables the e-training course suppliers 1) to express their e-training strategies, in the form of e-training course templates, using a common machine understandable way, and 2) to design and develop e-training courses using a reference set of predefined e-training course templates. As a result, a set of e-training course templates, which are following different e-training strategies (suitable for disabled people training), can be designed to facilitate the development of e-training courses that adopt these strategies. Fig. 2 presents the learning activities flow of two typical e-training course templates, namely, the “competence-based training” and the “project-based learning” templates. The eAccess2Learn Repository includes a reference set of e-training course templates, which are produced by active e-training course suppliers based on their best practices.
Fig. 3 presents snapshots of the eAccess2Learn Learning Design Toolkit, which provides e-training courses suppliers with a graphical user-friendly interface for creating e-training courses conformant with IMS Learning Design Specification [ 32] and packaging them along with their related e-training resources. Furthermore, by using the eAccess2Learn Learning Design Toolkit, e-training courses suppliers can exchange e-training strategies and/or courses, assess their application at a local/national/global context of use, and reflect to the feedback for further improvements to either e-training strategies or e-training courses.
3.3.2 eAccess2Learn Guidelines and Style Sheets for Developing Accessible Web-Based Training Content This is a service that includes the provision of 1) a set of mandatory guidelines, based on the W3C Web Content Accessibility Guidelines 1.0 [ 18], which can be followed by the e-training content suppliers to ensure that their newly produced e-training resources meet accessibility requirements for visually impaired and motor-disabled people and 2) a set of cascading style sheets (CSS) for HTML-based content that facilitate e-training content suppliers to transform the presentation of the HTML elements (e.g., text size/color, foreground/background color, buttons, links, etc.) of their existing e-training resources, so as to be understandable and navigable from low-vision, color-blind, and motor-disabled people.
The eAccess2Learn guidelines aim to address three general dimensions, namely, the presentation, understandability, and navigability of the e-training resources. These dimensions are similar with the different themes of accessible design that the Web Content Accessibility Guidelines address [ 18], [ 19]. Fig. 4 presents an implementation example of the eAccess2Learn Guidelines for developing accessible web-based training content. More specifically, since text is considered potentially accessible to all users as it can be handled by 1) screen readers, 2) nonvisual browsers, and 3) braille readers [ 18], [ 19], nontextual information (images, applets, sounds, multimedia presentations) should be followed by textual equivalents. Additionally, especially for color-blind people, information conveyed with color should be also available without it, through alternative descriptions.
Moreover, the presentation of the content in HTML pages should be controlled with style sheets rather than with presentation elements and attributes applied directly to the HTML elements [ 18], [ 19]. For this purpose, three different style sheets have been developed for controlling the presentation of HTML-based content for three disability categories, namely, motor-disabled, low-vision, and color-blind people. Fig. 5 presents the application of the eAccess2Learn Accessibility Style Sheets to the same HTML content. The HTML content is accordingly transformed to be understandable and navigable for visually impaired (low vision and color-blind) and motor-disabled people. More precisely, when the style sheet for color-blind people is applied, the HTML page is transformed so only black and white colors are used. In case the style sheet for low vision is applied, the HTML page is transformed so the font size becomes larger and the contrast between background and foreground becomes higher. Additionally, the hyperlinks and the buttons of the HTML page are transformed to become larger and with higher contrast compared to the background. Finally, when the motor-disabled style sheet is applied, the hyperlinks become larger, to enable persons with motor disabilities to click more easily on the hyperlinks.
3.3.3 eAccess2Learn Accessible Learning Objects Metadata Authoring Toolkit This is a software tool that facilitates the e-training content suppliers and e-training courses suppliers to author educational metadata for their e-training resources and e-training courses, as well as organizing and offering e-training resources and courses through the eAccess2Learn Web Repository. Fig. 6 presents screenshots of the eAccess2Learn Accessible Learning Objects Metadata Authoring Toolkit. This toolkit aims to provide e-training content suppliers and e-training courses suppliers with a user-friendly authoring wizard for describing their e-training resources and courses with educational and accessibility metadata conformant with the IEEE Learning Objects Metadata Standard [ 26]. Moreover, by using the eAccess2Learn Accessible Learning Objects Metadata Authoring Toolkit, e-training course suppliers can create and offer descriptions of available e-training courses with emphasis to accessibility aspects, so as to enable e-training services providers to make more informed decisions during the design of their e-training programs.
In order to handle the accessibility characteristics of the e-training resources and courses, we have proposed extensions to the IEEE LOM standard through an IEEE LOM Application Profile, which was reported in [ 37]. More specifically, we have proposed the extension of Category 4.8 (Technical) with information about the use of colors in learning objects, so visually impaired people can be able to access appropriately developed e-training resources. Table 1 summarizes these extensions.
Additionally, we have proposed extensions to the value space of the metadata element [Kind] in Category 4.7 (Relation) with information about the relationship of e-training resources with visual, text, or auditory alternatives. Table 2 summarizes these value space extensions.
3.3.4 eAccess2Learn Web Repository This is a web-based platform enabling e-training content suppliers and e-training course suppliers to share their e-training resources and e-training courses. Moreover, the eAccess2Learn Web Repository ( http://www.eaccess2learn. eu) offers to the e-training services providers the ability to search and retrieve e-training courses, which they can integrate to their services. Additionally, the eAccess2Learn Web Repository is conformant with Web Content Accessibility Guidelines 1.0 [ 18], enabling direct access from users with certain disabilities, namely, motor-disabled and visually impaired users. The functionalities of the eAccess2Learn Web Repository can be summarized as follows:
Submit and Store: E-training content suppliers and e-training courses suppliers are able to submit and store e-training resources and courses to the eAccess2Learn Web Repository along with their related educational metadata, which has been previously developed by using the eAccess2Learning Accessible Learning Objects Metadata Authoring Toolkit.
Search and Retrieve: All user categories of the eAccess2Learn Web Repository are able to search and retrieve e-training resources and courses by using searching criteria, which are matched with the educational metadata of these resources and courses.
Download: All user categories of the eAccess2Learn Web Repository are able to download e-training resources and courses and use them through other e-training systems and platforms. Moreover, the users are able to download the metadata record of an e-training resource or an e-training course and import it to other e-training systems and platforms or repositories, so as to be searchable and retrievable.
Rate/Comment: All user categories of the eAccess2Learn Web Repository are able to provide their ratings and comments for the e-training resources and e-training courses stored in the eAccess2Learn Web Repository. These ratings and comments could be related with the impressions of the users who have used a specific e-training resource/course.
Fig. 7 presents screenshots of the eAccess2Learn Web Repository functionalities. More precisely, the searching mechanism of the eAccess2Learn Repository is presented, where the users can search e-training resources and courses by using searching criteria, which are matched with the educational metadata of these resources and courses. Next, the searching results are presented, where the users can browse and download e-training resources and courses by previewing their educational metadata. The next screenshot presents the uploading mechanism of the eAccess2Learn Web Repository, where the users (e-training content suppliers and e-training courses suppliers) can upload their e-training resources and courses along with their related educational metadata records, so as to be searchable and retrievable from the searching mechanism of the repository. Finally, the last screenshot presents the rating/commenting mechanism, where the users can 1) provide their ratings and comments about e-training resources and courses included in the eAccess2Lern Web Repository and 2) browse the ratings and comments of other users of the eAccess2Learn Web Repository.
Objective 1: To validate the transformation of existing e-training resources to be fully accessible for both selected disabled user groups by using the eAccess2Learn Guidelines for Developing Accessible Web-Based Training Content.
Objective 2: To validate the transformation of the presentation of the same e-training resources with the use of the eAccess2Learn Accessibility Style Sheets for Developing Accessible Web-Based Training Content so as to be understandable and navigable for both selected disabled user groups.
Objective 3: To validate the interoperability of the educational metadata of the e-training resources and courses produced by the eAccess2Learn Accessible Learning Objects Metadata Authoring Toolkit.
Objective 4: To validate the interoperability of the e-training courses produced by the eAccess2Learn Learning Design Toolkit.
Objective 5: To validate the reuse of e-training resources within different e-training courses produced by using the eAccess2Learn Framework Tools.
Objective 6: To validate the reuse of the e-training course templates within different e-training courses, as well as among different disabled user groups (namely, motor-disabled and low-vision people) by using the eAccess2Learn Framework Tools.
Step 1: During this step, each participant developed 30 accessible e-training resources by following the eAccess2Learn Guidelines for Developing Accessible Web-Based Training Content. The outcome of step 1 was 30 accessible e-training resources.
Step 2: During this step, each participant validated and corrected the markup HTML syntax of the developed e-training resources using the W3C Markup Validation Service.
Step 3: During this step, each participant transformed the presentation of the HTML elements of the 30 developed accessible e-training resources by using the eAccess2Learn Accessibility Style Sheets, so as to be understandable and navigable for low-vision and motor-disabled people, producing 30 accessible e-training resources for each disabled user group (60 in total).
Step 4: Finally, each participant characterized with educational metadata the developed accessible e-training resources for both disabled user groups and uploaded them to the eAccess2Learn Web Repository by using the uploading mechanism of the repository.
Step 1: First, each participant selected one e-training course template from the reference set of e-training course templates (developed by typical e-training course suppliers based on their best practices), which are embedded in the eAccess2Learn Learning Design Toolkit, so as to develop his/her e-training courses based on that template. The selection of the e-training course template from each participant was based on the following criteria: 1) the conformance of the e-training course templates educational objectives with the educational objectives that each participant was aiming to address with its e-training courses, and 2) the accessibility needs of the two targeted disabled user groups.
Step 2: Next, each participant used the searching mechanisms of the eAccess2Learn Repository, so as to search and retrieve appropriate e-training resources suitable for 1) the learning activities of the selected e-training course template, 2) the accessibility needs of each disabled user group, and 3) the subject domains that have been selected by each participant for the development of their e-training courses.
Step 3: During this step, each participant used the eAccess2Learn Learning Design Toolkit to produce five e-training courses, represented in the form of IMS Learning Design Packages for each of the two disabled user groups, based on the selected e-training course template and the e-training resources selected from the eAccess2Learn Web Repository.
Step 4: Finally, each participant characterized with educational metadata the developed e-training courses for the two disabled user groups and uploaded them to the eAccess2Learn Web Repository by using the uploading mechanism of the repository.
Existing e-training resources can be transformed to accessible, so as to be understandable and navigable for the two disabled user groups.
Existing e-training resources can be reused within different e-training courses, while retaining their interoperability between various e-training systems and platforms.
Existing e-training course templates can be reused within different e-training courses, as well as, among different disabled user groups (in our case, the motor-disabled and the visually impaired people)
The authors are with the Department of Digital Systems, University of Piraeus & Informatics and Telematics Institute, Centre for Research and Technology Hellas, 150 Androutsou Str., Piraeus, GR-18532, Greece. E-mail: email@example.com, firstname.lastname@example.org.
Manuscript received 25 Aug. 2010; revised 30 Nov. 2010; accepted 23 Dec. 2010; published online 22 Mar. 2011.
For information on obtaining reprints of this article, please send e-mail to: email@example.com, and reference IEEECS Log Number TLT-2010-08-0109.
Digital Object Identifier no. 10.1109/TLT.2011.11.
Demetrios G. Sampson received the diploma in electrical engineering from the Democritus University of Thrace, Greece, in 1989 and the PhD degree in electronic systems engineering from the University of Essex, United Kingdom, in 1995. Currently, he is an associate professor of e-learning in the Department of Digital Systems, University of Piraeus, Greece, and a senior researcher at the Informatics and Telematics Institute (ITI), Centre for Research and Technology Hellas (CERTH). His main research interests are in the areas of technology-enhanced learning. He is the coauthor of more than 250 publications in scientific books, journals, and conferences with at least 1,000 known citations (h-index: 19). He has received seven Best Paper Awards from international conferences on advanced learning technologies. He is the coeditor-in-chief of the Educational Technology and Society Journal (impact factor 1.066, 2010), associate editor of the IEEE Transactions on Learning Technologies, member of the editorial board of 17 international journals, and guest coeditor for 17 special issues of international journals. His participation in the organization of international/national scientific conferences includes: general chair for 13 international conferences, program committee chair for 15 international conferences, and membership in 241 program committees of international conferences. He has been a keynote/invited speaker for 19 international conferences and 16 national conferences. He is a senior member of the IEEE and the elected chair of the IEEE Computer Society Technical Committee on Learning Technology (LTTC).
Panagiotis Zervas received the diploma in electronics and computer engineering from the Technical University of Crete, Greece, in 2002 and a master's degree in computational science from the Department of Informatics and Telecommunications of the National and Kapodistrian University of Athens, Greece, in 2004. Currently, he is a PhD candidate in the Department of Digital Systems, University of Piraeus, Greece, and is a member of the Informatics and Telematics Institute (ITI) of the Centre for Research and Technology Hellas (CERTH). His main scientific interests are in the areas of technology-enhanced learning. He is the coauthor of more than 30 publications in scientific journals and conferences. He received the Best Poster Award from the IEEE International Conference on Advanced Learning Technologies (July 2011), the Best Paper Award from the Second International Conference on Intelligent Networking and Collaborative Systems (2010), the Best Short Paper Award from the IEEE International Conference on Advanced Learning Technologies (July 2009), and the Best Poster Award from the IEEE International Conference on Advanced Learning Technologies (July 2007).