ACCMD Briefing

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This is the HTML version of the IMS AccessForAll Metadata Specification Briefing Paper (Word Format) - 64Kb.

What is the ACCMD Specification? The ACCMD Specification defines the meta-data that can be used to describe a learning resource's accessibility and its ability to match a learner's preferences. It works in  conjunction with the IMS ACCLIP (Accessibility for Learner Information Package) Specification, and provides guidance on how to make the two specifications work together. ACCMD has two main purposes:

 to define the characteristics of a resource; in order to facilitate the discovery of accessible resources, which match a learner's preferences.

The ACCMD Specification consists of four documents:   ACCMD Overview - explains the role and purpose of the specification.  ACCMD Information Model - defines the actual elements and data structures for representing AccessForAll (accessibility) meta-data.  ACCMD XML (eXtensible Mark-up Language) Schema Binding - describes how these elements are represented in XML.  ACCMD Best Practice and Implementation Guide - gives implementation guidance and suggestions for best practice.

(Note that the specification does not describe how to create accessible content, which is covered by the IMS Accessibility and the W3C (World Wide Web Consortium) Guidelines and specifications). It is available free of charge from http://www.imsglobal.org/accessibility/#accmd.

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Why is it useful? The ACCMD Specification enables accessible resources to be sought and presented to the learner. Implementing both the ACCLIP Specification, which defines a learner's   preferences, and the ACCMD Specification, which defines the characteristics of a resource, should therefore enable e-learning systems to determine what resources are accessible to     which learners.

However, there is more to the ACCMD Specification than just resource discovery - it also allows a resource to either be augmented by supplementary or substituted with equivalent alternative resources, thus providing the learner with a more suitable resource.

Therefore, if both specifications are implemented, learners will not only be able to specify how content should be displayed and controlled, but they will also be able to define any   alternative or supplementary resources that they might need.

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Related Specifications The ACCMD and ACCLIP Specifications both share the same definitions and attributes for the &lt;content&gt; element so that there is consistency between the two specifications. In order    to emphasise the closeness of the specifications, they have been termed the "AccessForAll Specifications".

Other relevant specifications include   Dublin Core Metadata - a standard for online meta-data which can be used for a number of purposes.</li>  IEEE LOM (Institute of Electrical and Electronic Engineers' Learning Object Metadata) - a profile for learning object meta-data.</li>  IMS Content Packaging Specification - AccessForAll meta-data should be included or referenced in any content package manifest that describes the package or its      associate resource.</li></ul>

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How does it work? The ACCMD Specification groups resources into two separate categories for meta-data:

  Primary resources - i.e. the initial or default resource; and</li>  Equivalent alternative resources - address the same learning objective as the primary resource but offer the resource in an alternative form.</li></ul>

Primary Resources It is assumed in the ACCMD Specification that authors of primary resources may not have the necessary accessibility knowledge, therefore primary resource meta-data elements have been kept to a minimum. The three basic elements are:

  &lt;primary&gt; (sensory modality) - i.e. whether the learner requires vision, hearing, touch, or text literacy (used particularly for learners with dyslexia) to       use the resource. This is not the same as the format of the resource, i.e. whether it is a JPEG, WAV, or RTF (Rich Text Format) for example, but describes the actual sensory       requirement necessary to access the resource. </li>

 &lt;earl&gt; - this element references EARL (Evaluation and Report Language) statements. However, in order for them to be useful, the resource's content and its structure must be independent of the actual presentation and should be marked up correctly. The EARL statements describe whether:

 the display (e.g. font colour, background colour, etc) can be transformed; and/or</li> the method of control (i.e. if a keyboard can be used instead of a mouse) is flexible.</li></ul> </li>

 &lt;equivalentResource&gt; - this is simply a pointer to an equivalent alternative resource. No other meta-data is required as it should be detailed in the    equivalent alternative resource itself. There may be pointers to zero or more equivalent alternative resources.</li></ul>

Equivalent Alternative Resources If the primary (i.e. initial) resource is not suitable for a learner, then an equivalent alternative resource must be found and displayed. A pointer to an equivalent alternative resource can be defined in the meta-data of the primary resource. In contrast to authors of primary resources, it is assumed that authors of these resources are likely to be more informed about accessibility, and so the meta-data is more detailed and closely matches elements in the ACCLIP Specification.

Equivalent alternative resources are of two types:   Supplementary resources - supplement the primary resource; for example, text captions for the soundtrack to a video can be considered as a supplementary resource. </li>

<li> Non-supplementary resources - act as a substitute for the primary resource. For example, a full text description which substitutes a diagram   showing how heat convection in water works could be offered as a non-supplementary resource to a learner who is unable to access graphics.</li></ul>

Once the equivalent alternative resources have been identified as being either supplementary or non-supplementary, meta-data relating to the ACCLIP &lt;content&gt; element must be added containing the following:

<ul> <li> &lt;alternativesToVisual&gt; - such as audio descriptions, long descriptions and colour avoidance;</li> <li> &lt;alternativesToText&gt; - such as graphic alternatives and sign language;</li> <li> &lt;alternativesToAuditory&gt; - such as captions, sign language;</li> <li> &lt;learnerScaffold&gt; - such as dictionary, calculator, thesaurus, etc. </li></ul> For example, an alternative resource for a video should state whether it is an alternative for the audio (e.g. captions) or for the visual (e.g. an audio description of the visual content). It should also be remembered that this information is described only in the context of its equivalence to the primary resource. Equivalent alternative resources are only ever allowed to have one primary resource and are never allowed to point to another equivalent alternative resource; otherwise circular references would be generated.

Granularity of Primary Learning Resources Many primary learning resources are likely to be made up of multiple files and objects (i.e. aggregated resources), but in order to determine the accessibility of the resource as a whole, learning resource should be dis-aggregated into its separate (i.e. atomic) parts and AccessForAll meta-data added to each component. If the atomic files have their own     AccessForAll meta-data, an e-learning system can then match the accessibility of each component against a learner's preferences and present equivalent alternatives if necessary. In this way, the aggregated resource can then be made accessible to the user. An aggregated resource, for example, could be an HTML (HyperText Mark-up Language) document containing text and JPEG images. At the atomic level, AccessForAll meta-data for each JPEG would contain the &lt;hasVisual&gt; attribute, whilst the text would contain the &lt;hasText&gt; attribute. At the aggregated level, the HTML document would contain both the &lt;hasVisual&gt; and   &lt;hasText&gt; attributes. There may also be pointers to equivalent resources for each component. For example, the meta-data for the JPEG files could contain pointers to  &lt;longdesc&gt; tags or descriptive text files.

An e-learning system parsing this AccessForAll meta-data would check the meta-data for each component (if it exists), find any equivalent alternative resources and then present the     resource according to the learner's preferences. Using the HTML document example mentioned above and assuming each component has complete AccessForAll meta-data, the system would match it with the learner's requirements and then present any alternatives to the JPEG images, if the learner has requested them.

If the atomic parts of the learning resource do not contain any AccessForAll meta-data, pointers to alternative equivalent resources or do not match the learner's preferences, then a     message should be displayed to the learner detailing this issue.

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What is required? An e-learning system should first seek to transform the primary resource via alternative styling (e.g. use of CSS (Cascading Style Sheets), etc) or alternative control methods (e.g. use of a keyboard instead of a mouse). However, if that does not meet the learner's requirements, then an alternative equivalent resource should be sought and presented. In any case, there must be a set of learner preferences (retrieved from an implementation of the ACCLIP Specification) and resources should contain AccessForAll meta-data (as defined in the ACCMD Specification).

If the learner does not have any preferences regarding the way in which content is displayed or controlled, then the primary resource should be displayed. On the other hand, if the resource does not have any AccessForAll meta-data but the learner has a set of preferences, then the learner should be notified via a system warning.

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Example Use Case and Implementations Aircraft Maintenance Hangar Use Case Learners completing a hands-on exercise in a noisy aircraft maintenance hangar have a set of (ACCLIP) preferences for working in such an environment. When they log on to the computer, they select their set of requirements for the hangar, which includes preferences for text transcripts or animated diagrams instead of audio content. When viewing learning resources (marked up using the ACCMD Specification), such as training videos with audio content, the system automatically retrieves and displays text captions or other alternative content and synchronises it to the original audio track. TILE (The Inclusive Learning Exchange) TILE is a learning object repository, which stores objects as atomic files, along with their general and AccessForAll meta-data. As a result, TILE can then respond to the user preferences by matching a user's requirements with the characteristics of the resources requested. There is also a TILE authoring tool for aggregating and publishing learning objects. It prompts resource authors to provide information about the resource's modality (i.e. whether it contains auditory, visual or tactile content), and about equivalent alternative resources and their accessibility properties. This information is stored in the resource's meta-data profile.

A user's ACCLIP profile is then parsed to determine whether the primary resource should be displayed, substituted or supplemented with an equivalent alternative resource, styled (e.g. from a CSS) or transformed (e.g. &lt;alt&gt; text provided for an image). The system retrieves the appropriate resource and presents it to the user.

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Other Briefings Other briefings in this series are available and include:

<ul> <li>Briefing: IMS Accessibility for Learner Information Package (ACCLIP) Specification - This specification provides a means of describing preferences so that learners can interact with an e-learning system regardless of disability, hardware or environment. </li>

<li>Briefing: IMS Guidelines for Developing Accessible Learning Applications (Accessibility Guidelines) - The Accessibility Guidelines provide a set of accessibility resources and recommendations for the e-learning community, so that online learning can be made accessible to everyone.</li></ul>

Information for this briefing has been taken from the IMS AccessForAll Meta-data Specification.

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