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This is a draft - please comment....


ISO/IEC 24751 is intended to facilitate the matching of individual user needs and preferences with digital resources that meet those needs and preferences. This matching might involve finding a suitable resource or interface, or format of a resource, or it might involve adaptation of the resource or its interface. It is intended to address mismatches between personal needs and preferences caused by any number of circumstances, including requirements related to client devices, environments, language proficiency or abilities. The terms and definitions within ISO/IEC 24751 are not medical or judgmental but functional; the purpose is not to point out flaws in digital resources with respect to accessibility and adaptability, but to facilitate the discovery and use of the most appropriate content and interface components for each user. 

In ISO/IEC 24751, it is recognized that users experience a disability when there is a mismatch between the user's needs (or preferences) and the perceptual experience delivered. Disability is therefore not viewed as a personal trait but as a consequence of the relationship between a user, the situation in which they are working, and an interactive environment or resource delivery system. An individual who is blind is not disabled when a resource is delivered in audio, but an individual who does not have the necessary background knowledge to understand the resource, or an individual who is listening to the resource in a noisy environment, is disabled. Given this re-framing, a resource is accessible when a user's needs can be addressed or matched (through adaptation, re-aggregation or substitution of digital interfaces or resources). Accessibility, in practice, is determined by the flexibility of the environment (with respect to presentation, control methods, structure, access mode, and intellectual supports, for example) and the availability of adequate alternative-but-equivalent interfaces, content and activities. The needs and preferences of a user may arise from the user's context or environment, the technical requirements of the user's device, the tools available (e.g. assistive technologies such as Braille devices, voice recognition systems, alternative keyboards, etc.), the user's background, or a disability in the traditional medical sense. Accessible ‘systems’ adjust the user interface or configuration of the interactive environment, and locate needed resources, matched and adjusted to the needs and preferences of the individual user.

This Framework Part 1 of ISO/IEC 24751 provides a common framework for additional parts. These additional parts may include:

  1. Part 2 that describes in detail the provision, maintenance, availability, form and use of an open, online, digital registry to be called the AccessForAll Registry;
  2. Other parts that specify the definition of data elements to be registered in the AccessForAll (or other conformant registries). It may also specify classes of data elements, such as those associated with a class of visibility, or classes such as those that are mandatory, recommended, or otherwise, and
  3. other parts as deemed necessary to support implementation and provide interoperability and efficiency of this standard.

It is intended that the registry will enable the registration of common terms that can be used to describe users' needs and preferences for the provision of interfaces and resources. This may involve registration of terms, of schema, or other documents that will be machine-readable and, where appropriate, human readable.

NOTE 1 Many jurisdictional domains have instituted policies or legislation that require equal access to information for individuals with disabilities (as defined by the World Health Organization). ISO/IEC 24751 can be used to assist in meeting these requirements (see Annex C for a list of example policies and legislation).


1  ISO/IEC 24751 is intended to facilitate the matching of resources to user's individual requirements by providing common terms for describing those requirements so they can be matched to resources that satisfy the requirements.
1.2 Exclusions

This part of ISO/IEC 24751 does not describe how to create accessible content.  

NOTE Other work exists and standards are under development that describe how resources can be made more accessible [1].

Metadata to assert compliance to an accessibility specification or standard is not within the scope of this standard.

This part of ISO/IEC 24751 does not (nor do ISO/IEC 24751-2 and ISO/IEC 24751-3) define how to deal with types and roles of Persons, (and two sub-types of Person namely organization and public administration) [2]. <span style="color: #ff00ff">Editors' Note -</span> <span style="color: #ff00ff">Is this necessary?</span>

[1] See for example W3C/WAI Web Content Accessibility Guidelines [W3C/WAI, WCAG], ISO 15836, ISO 15706, other standards of ISO/TC 46 and ISO/IEC JTC 1/SC 29, as well as standards being developed by ISO/IEC JTC 1/SC 36.
[2] See further ISO/IEC 14662:2004, Information technology — Open-edi reference model and the ISO/IEC 15944 multi-part e-business standard.

1.3 Aspects not currently addressed Editors' Note - given the registry, many things if appropriate will be addressed so excluding things is not necessary

ISO/IEC 24751 does not currently support individual needs and preferences and resource descriptions related to non-digital resources.

2. Terms and Definitions

Editors' Note - as many of these will not be used in the text of the standard, they are here just is case but can be discarded. They are copied from N 24751 and numbering has not be adjusted.

2 Terms and definitions

For the purposes of this document, the following terms and definitions apply.


access for all


approach to providing accessibility (2.2) in a computer-mediated environment in which the digital resources (2.11) and their method of delivery are matched to the needs and preferences of the user [IMS AccessForAll Meta-data Specification Version 1]  [IMS AccessForAll Meta-data Specification Version 1]



usability (2.26) of a product, service, environment or facility by individuals (2.20) with the widest range of capabilities

NOTE 1 Although “accessibility” typically addresses users who have a disability, the concept is not limited to disability issues.

NOTE 2 Adapted from ISO/TS 16071:2003, 3.2


access mode

human sense perceptual system or cognitive faculty through which a user may process or perceive the content of a digital resource (2.11)



⟨e-learning⟩ ability of a digital resource (2.11) or delivery system to adjust the presentation, control methods, structure, access mode (2.3), and user supports, when delivered



⟨e-learning⟩ digital resource (2.11) that presents the intellectual content (2.23) of all or part of another digital resource (2.11)  NOTE Adaptations can also include the adjustment of the  presentation, control methods, access mode, structure and user supports.


AfA agent

someone, i.e. a real person, or something, i.e. automatons (2.7), acting on behalf of an individual (2.20) in a clearly specified capacity in an access for all (2.1) context

NOTE Adapted from definition of “agent” in ISO/IEC 15944-1:2002, 3.1.


assistive technology

alternative access system specialized software and/or hardware used in place of or in addition to commonly used software or hardware for control, display (2.15) or processing

EXAMPLES Screen reader, alternative keyboard, refreshable Braille device, screen magnifier.


data element, term 

unit of data for which the definition, identification, representation and permissible values are specified by means of a set of attributes

 [ISO/IEC 11179-1:2004, 3.3.8]  [ISO/CEI 11179-1:2004, 3.3.8]


dataset, term set

identifiable collection of data  

NOTE A dataset can be a smaller grouping of data which, though limited by some constraint such as spatial extent or feature type, is located physically within a larger dataset. Theoretically, a dataset can be as small as a single feature or feature attribute contained within a larger dataset. A hardcopy map or chart can be considered a dataset.


digital resource DR

any type of resource that can be transmitted over and/or accessed via an information technology system (2.22)

NOTE A digital resource can be referencedvia an unambiguous and stable identifier in a recognized identification system (e.g. ISBN, ISAN, UPC/EAN, URI).


digital resource delivery

presentation of a digital resource (2.11) by a display (2.15)



⟨digital resource delivery⟩ any obstacle to the use of a digital resource (2.11) experienced because of a mismatch between the needs of a user and the digital resource (2.11) delivered

NOTE 1 Disability in an AfA context is not a personal trait but a consequence of the relationship between the user and their resource system. 

NOTE 2 In an e-learning context, disability refers to a mismatch between the needs of a learner and both the educational resource and/or the method of delivery.


disability ⟨medical perspective⟩

any restriction or lack [resulting from an impairment (2.19)] of ability to perform an activity in the manner, or within the range, considered normal for a human being NOTE 1 This definition of “disability” is included to ensure that users who may have “legal rights” to assistive technologies are served.

NOTE 2 Adapted from World Health Organization Document A29/INFDOCI/1, Geneva, Switzerland, 1976.



rendering or presentation of a user interface and/or digital resource (2.11) in a range of access modes (2.3)

NOTE Access modes include, but are not limited to, visual, auditory, olfactory, textual and tactile.


display transformability

characteristic of a digital resource (2.11) that supports changes to specific aspects of its display (2.15)

NOTE See the coded domain in ISO/IEC 24751-3:2008, B.3.


display transformation


restyling or reconfiguration of the rendering or presentation of a user interface and/or digital resource (2.11)



⟨medical perspective⟩ any loss or abnormality of psychological, physiological, or anatomical structure or function

NOTE Adapted from World Health Organization Document A29/INFDOCI/1, Geneva, Switzerland, 1976.



human being, i.e. a natural person, who acts as a distinct indivisible entity or is considered as such

NOTE Adapted from ISO/IEC 15944-1:2002, 3.28. 


individualized accessibility

⟨e-learning⟩ facility of an IT system (2.22) based learning environment to address the needs of an individual as learner [through adaptation (2.5), re- aggregation and substitution]

NOTE Accessibility is determined by the flexibility of the education environment (with respect to presentation, control methods, structure, access mode and learner supports) and the availability of equivalent content deemed to be adequate alternatives.


information technology system IT system

set of one or more computers, associated software, peripherals, terminals, human operations, physical processes, information transfer means, that form an autonomous whole, capable of performing information processing and/or information transfer  [ISO/IEC 14662:2004, 3.1.8]  


intellectual content

recorded information of a digital resource (2.11) independent of its representation and/or access mode (2.3)



system of signs for communication, usually consisting of a vocabulary and rules

 [ISO 5127:2001,]  


matchmaker service

an online service that determines the user preference set to be used for discovery and delivery of resources and the interfaces to them, or an online service that matches resources and interfaces to a user's preference set at any time


resolved user preference set

a set of user preferences that no longer contain conditions because they have been resolved either by being satisfied or found to be irrelevant at the time



extent to which a product can be used by specified users to achieve specified goals, with effectiveness, efficiency and satisfaction, in a specified context of use

 [ISO 9241-11:1998, 3.1]  [ISO 9241-11:1998, 3.1]


user experience

those aspects of interfaces or resources that a person experiences including but not limited to interfaces, presentations, augmentations (e.g. captions, descriptions), alternate resources (e.g. a different way to learn about gravity that doesn’t require vision), language, culture, and cognitive complexity.


user preferences profile

a set of user preferences including the conditions under which they are to operate

3 Symbols and abbreviations

AfA access for all

DR digital resource

DCMI Dublin Core Metadata Initiative

DCMT Dublin Core Metadata Terms

DT display transformation

EDI electronic data interchange

FDT Formal Description Technique

FSV Functional Services View IMS IMS Global Learning Consortium

HIE Human Interface Equivalent

ISO International Organization for Standardization

IEC International Electrotechnical Commission

IT information technology

IT system information technology system

JTC 1 Joint Technical Committee 1 (of ISO/IEC)

MLR Metadata for Learning Resources standard (ISO/IEC N 19788)

RS Registration Schema

UML Unified Modelling Language

W3C World Wide Web Consortium

W3C/WAI WCAG World Wide Web Consortium/Web Accessibility Initiative Web Content Accessibility Guidelines

4. Basic Principles

4.1 The Matching Process

This standard enables a matching process by providing for common terms to be used for descriptions of user requirements and the relevant characteristics of resources so they can be matched. It does not specify how matches are to be made although examples of systems that make matches are provided in Appendix 1.

The goal is to facilitate the provision of a user experience that matches the needs and preferences of a user by providing a framework for the definition of common terms describing:

  • user needs and preferences and user experiences available from a device and resource


  • a method and format for maintaining and publishing a registry of such common terms.

4.2 Basic Principles for this standard include the following:

  1. It is envisaged that descriptions of requirements may be specified by users or generated by suitable algorithms but, in both cases, users' choices will be given priority in determining the profile of requirements they want to use at any time.
  2. It is understood that some users will have conditional requirements such as "from 8 am to 6 pm I would like white text on black but from 6 pm to 8 am I would like  yellow text on blue".
  3. Some users will specify requirements without which they cannot perceive a resource, essential requirements, needs, and some users will also want to specify preferences in cases where they can manage without the requirement but find it easier if they can have it.
  4. The definition of terms will be achieved interoperable with ISO/IEC N 19788.

4.2 Extending the Standard

This multi-part standard can be extended by adding additional parts. In general, the standard will be extended by registration of new terms (data elements) and other resources on the AccessForAll Registry according to this standard and, in particular, Part 2 of this standard.

4.3 Disability and accessibility

Metadata can be used for two accessibility related purposes: to record compliance to an accessibility specification or standard (e.g. for adherence to legislated procurement policies) or to enable the delivery of resources that meet a user's needs and preferences. This multi-part standard addresses the latter purpose. Metadata to assert compliance to an accessibility specification or standard is not within the scope of this standard.

This standard facilitates the selection for an individual user of appropriate digital resources when available thereby providing user experiences that adapt to individual needs. Because these specifications offer a modular approach to accessibility, by defining each aspect of a user preference or resource characteristic separately, systems can determine in individual cases if a resource is accessible, a facility that is not supported by existing accessibility guidelines.

The Access for All resource descriptions are not merely intended to assist with aspects of resource discovery. The AccessForAll Registry of resource descriptors and this overall standard provide an interoperable framework that supports the substitution and augmentation of a resource or component of a resource with an adaptation or component as required by the accessibility needs and preferences of each individual user. For example a textual caption could be added to a video when required by a user with a hearing impairment or in a noisy environment. Alternatively an interactive resource requiring a mouse for operation could be replaced with a resource that can be controlled using a keyboard or keyboard emulator for a user with a mobility impairment or a user operating a device without a mouse.

The complementary aspects of this standard address several challenges including:

  • • initial discovery of material having appropriate accessibility support;  
  • • adjustment (adaptation) of control and display characteristics of digital resources to meet a user's accessibility needs and preferences; and
  • • discovery of appropriate alternative or supplementary representations of desired digital resources. 

This standard exploits the capability of an IT system to translate or transform user interfaces and digital resources for delivery. The first approach to meeting the specific needs and preferences of a user would be to transform the digital resource through alternative presentation styling or through the provision of alternative control methods (e.g. keyboard shortcuts).  This can sometimes be accomplished through the configuration options of the operating system. the rendering options of the application, the styling of the user interface and content, or through an assistive technology. If a digital resource cannot be adequately transformed an alternative digital resource will be required.

The standard will define description terms for profiles of the needs and preferences that can be selected by a user or their agent. Within the user preferences profile, there will be provision for preferences to be described using

  • a property definition (to be identified by URL);
  • a value set for that property, and
  • conditions for the operation of that preference.

At any time, a user's set of resolved preferences will be those preferences that apply by satisfaction of the stated conditions. Where there is a conflict between preference values, the first occurrence within the set will be given priority, independently of when the preferences were stated. Editor's note: this may not work because what if I want to override what preference is applying right now? do I have to get out the profile and re-order it? (Actually, I think the wizard should do this - LN.)

4.4 The importance of interoperability and consistent implementation 

While interoperability is always important, the importance is heightened for users who depend upon assistive technologies or specialized devices such as refreshable Braille displays enlarged keyboards or voice recognition systems. Many individuals with a physical sensory or intellectual impairment are dependent on assistive technologies to use an IT system. From an information technology developer's perspective every individual using an assistive technology potentially represents an external system that needs to interoperate. In fact, because of the diversity of assistive technologies, every user of an assistive technology potentially represents a unique external system that needs to interoperate. Additionally, in order to function, each assistive technology needs to interoperate with a large array of interfaces and applications. The user base and development base of assistive technologies are very small and under-resourced. For this reason it is critical that there is consistency in the implementation and interpretation of these standards to increase the likelihood of interoperability for assistive technologies.

Whether using an assistive technology or not, user needs and preferences of individuals with a disability (from a medical perspective) are frequently very particular with little or no room for variance. A slight variation in font size, button size or background colour, for example, can be the difference between an accessible digital resource and an unusable one. Ensuring access for users whose choice of access modes is restricted by impairment often requires exact matching of a digital resource with a user's requirements: in such a case it is not a matter of convenience or optional refinement but one of utmost importance. As a result it is necessary for systems to agree upon well-defined interfaces and for the specification to deter free non-conformant extension in its usage. A strictly defined approach is taken in this multi-part standard to support maximum interoperability and minimize costs.

Part 1 (Section 5) of this standard provides an abstract model for metadata for this standard. It is based on the Resource Description Framework (W3C …) and interoperable with the Metadata for Learning Resources standard, ISO JTC1 N:19788, and Dublin Core Metadata (ISO N:???).

"RDF has the happy characteristic that "it can say anything about anything." This means that, in principle, any resource can have any property and there is no requirement that any two resources have the same set of properties, even if they have the same type or types. In practice, though, the properties that are set on resources usually follow regular patterns that are dictated by the uses of those resources. Although a particular resource might have arbitrary properties, when viewed from the perspective of a particular application or use case, the set of properties and property values that are appropriate for that resource in that application will often be predictable and constrained. For example, if a server has resources that represent software products and bugs, for the purposes of displaying information in tabular formats, creating and updating resources, or other purposes, a client might want to know what properties software products and bugs have on that server,. The Basic Profile Validation and Constraints specification aims to capture information about those properties and constraints."


By providing for maximum interoperability of AccessForAll metadata, this standard not only caters for accessibility concerns but also makes it easier for general systems to include AccessForAll metadata.

5 Abstract model

Editors' note: there is a lot to be done here

A graphic and textual representation of an abstract model of the Parts and processes described in this multi-part standard, including those related to the AccessForAll Registry, is presented in this Clause. 

Readers not familiar with UML class diagrams should note that lines starting with a block-diamond should be read as “contains a” or “has a” (for example “a needs and preferences has zero or more contextual descriptions”). Other relationships are labelled appropriately.

Figure 1: the creation of a user's profile of requirements and provision of a suitable resource

Figure 2 “Matching Process diagram” illustrates a possible process for matching a digital resource to a user's needs and preferences represented as an UML process diagram.

 6 Specification of MLR data elements  

6.1 Introduction

A primary principle of this part of ISO/IEC 24751 is that a common set of attributes specifies the essential characteristics of each data element. This clause 6, specification of data elements, defines the attributes of data elements and rules for the values of those attributes.

6.2 Data element specification attributes

The identification of data elements must be documented completely. This process is independent of how information system developers and implementers structure their database(s), (e.g., as resource repositories, as micro formats…). This is achieved through the use of data element specifications. A data element specification consists of an identifier (for the data element specification) and a (defined) list of data element attributes with rules for the values of those attributes. Each data element specification has the following attributes:

  • Identifier (data element specification identifier)
  • Property name (data element name)
  • Definition (data element definition)
  • Linguistic indicator (data element linguistic indicator)
  • Domain (data element domain)
  • Range (data element range)
  • Content value rules
  • Refines
  • Example(s)
  • Note(s)

7 Multilinguality

Editors' note: how this is handled in the registry etc needs to be clarified here....

8 Conformance

This document is a framework document and as such there is no conformance to this part of the standard. Requirements for conformance are specified in successive parts of this standard. 

ISO/IEC 24751-2 AccessForAll Registry conformance is dependent on the function or role played by the conformant technology or application.

ISO/IEC-3 data element conformance depends upon publication data elements.

of free (no-cost) Digital resources are conformant when the metadata record of the digital IT systems are conformant when they gather and/or process Personal Needs and Preference descriptions as specified in ISO/IEC 24751 to deliver digital resources that match each user's needs and preferences.

Metadata authoring tools are conformant if they assist in authoring metadata that includes data elements as specified in ISO/IEC 24751.

Assistive technologies in a specific class are conformant when they respond to the generic elements of ISO/IEC 24751 that apply to that class (e.g., screen readers would respond to screen reader elements). Editors’ note: this notion of ‘generic’ has to be sorted.

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