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1EdTech Content Packaging Information Model Version 1.1.4 Final Specification |
Copyright © 2004 1EdTech Consortium, Inc. All Rights Reserved.
The 1EdTech Logo is a registered trademark of 1EdTech Consortium, Inc.
Document Name: 1EdTech Content Packaging Information Model
Revision: 04 October 2004
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Copyright © 2004 1EdTech Consortium. All Rights Reserved.
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Table of Contents
1. Introduction
1.1 Overview
1.2 Scope and Context
1.3 Structure of this Document
1.4 Nomenclature
1.5 References
2. 1EdTech Content Packaging Conceptual Model
2.1 Key Elements
2.2 Standard Name for the Manifest File
3. Extensibility
4. Manifest Elements
4.1 sub-Manifests
4.2 Href URL Construction Algorithm
About This Document
List of Contributors
Revision History
Index
1. Introduction
1.1 Overview
The 1EdTech Content Packaging (CP) Information Model describes data structures that are used to provide interoperability of Internet based content with content creation tools, learning management systems (LMS), and run time environments. The objective of the 1EdTech CP Information Model is to define a standardized set of structures that can be used to exchange content. These structures provide the basis for standardized data bindings that allow software developers and implementers to create instructional materials that interoperate across authoring tools, LMSs, and run time environments that have been developed independently by various software developers.
Note: The scope of the 1EdTech CP specification is focused on defining interoperability between systems that wish to import, export, aggregate, and disaggregate Packages of content. Future documents comprising the 1EdTech Content specification will address requirements regarding content data models and communication between run time environments and LMSs.
1.2 Scope and Context
This document is the 1EdTech CP Information Model specification. As such it will be used as the basis for the production of the following documents:
- 1EdTech Content Packaging XML Binding v1.1.4 [CP, 04b];
- 1EdTech Content Packaging Best Practice and Implementation Guide v1.1.4 [CP, 04c].
Version 1.1.4 is a maintenance release update to the version 1.1.3 specification and a description of the changes is given in the accompanying amendment document [CP, 04d].
Information on possible future development of the Content Packaging specification can be found in Appendix D of the Best Practices Guide [CP,04c].
1.3 Structure of this Document
The structure of the rest of this document is:
1.4 Nomenclature
| CPI | Content & Packaging Interchange |
| DTD | Document Type Definition |
| W3C | World Wide Web Consortium |
| XML | Extensible Mark-up Language |
1.5 References
2. 1EdTech Content Packaging Conceptual Model
Figure 2.1 is a conceptual diagram that illustrates the components of the 1EdTech Content Packaging Information Model. As indicated in the 1EdTech Content Packaging Best Practice Guide, this is part of the larger 1EdTech Content Framework, which forms the basis for this and future specifications.
2.1 Key Elements
The 1EdTech Package depicted in Figure 2.1 consists of two major elements: a special XML file describing the content organization and resources in a Package, and the file resources being described by the XML. The special XML file is called the 1EdTech Manifest file, because course content and organization is described in the context of 'manifests'. Once a Package has been incorporated into a single file for transportation, it is called a Package Interchange File. The relationship of these parts to the content container is described below:
Package Interchange File - a single file, (e.g., '.zip', '.jar', '.cab') which includes a top-level manifest file named "imsmanifest.xml" and all other files as identified by the Manifest. A Package Interchange File is a concise Web delivery format, a means of transporting related, structured information. PKZip v2.04g (.zip) is recommended as the default Package Interchange File format. Any ZIP file format MUST conform to RFC1951.
Package - a logical directory, which includes a specially named XML file, any XML control documents it directly references (such as a DTD or XSD file), and contains the actual file resources. The file resources may be organized in sub-directories.
- Top-level Manifest - a mandatory XML element describing the Package itself. It may also contain optional sub-Manifests. Each instance of a manifest contains the following sections:
- Meta-data section - an XML element describing a manifest as a whole;
- Organizations section - an XML element describing zero, one, or multiple organizations of the content within a manifest;
- Resources section - an XML element containing references to all of the actual resources and media elements needed for a manifest, including meta-data describing the resources, and references to any external files;
- sub-Manifest - one or more optional, logically nested manifests;
- File Resources - these are the actual media elements, text files, graphics, and other resources as described by the manifest(s). The file resources may be organized in sub-directories.
Package - A Package represents a unit of usable (and reusable) content. This may be part of a course that has instructional relevance outside of a course organization and can be delivered independently, as an entire course or as a collection of courses. Once a Package arrives at its destination to a run time service, such as an LMS vendor, the Package must allow itself to be aggregated or disaggregated into other Packages. A Package must be able to stand alone; that is, it must contain all the information needed to use the contents for learning when it has been unpacked.
Packages are not required to be incorporated into a Package Interchange File. A Package may also be distributed on a CD-ROM or other removable media without being compressed into a single file. An 1EdTech Manifest file and any other supporting XML files required by it (DTD, XSD) must be at the root of the distribution medium.
Manifest - A manifest is a description in XML of the resources comprising meaningful instruction. A manifest may also contain zero or more static ways of organizing the instructional resources for presentation.
The scope of manifest is elastic. A manifest can describe part of a course that can stand by itself outside of the context of a course (an instructional object), an entire course, or a collection of courses. The decision is given to content developers to describe their content in the way they want it to be considered for aggregation or disaggregation. The general rule is that a Package always contains a single top-level manifest that may contain one or more sub-Manifests. The top-level manifest always describes the Package. Any nested sub-Manifests describe the content at the level to which the sub-Manifest is scoped, such as a course, instructional object, or other.
For example, if all content comprising a course is so tightly coupled that no part of it may be presented out of the course context, a content developer would want to a single manifest to describe that course's resources and organization. However, content developers who create "instructional objects" that could be recombined with other instructional objects to create different course presentations would want to describe each instructional object in its own manifest, then aggregate those manifests into a higher-level manifest containing a course organization. Finally, a content developer who wants to move multiple courses in a single Package (a curriculum), would use a top-level manifest to contain each course-level manifest and any instructional object manifests that each course might contain.
Resource - The resources described in the manifest are assets such as Web pages, media files, text files, assessment objects or other pieces of data in file form. Resources may also include assets that are outside the Package but available through a URL, or collections of resources described by sub-Manifests. The combination of resources is generally categorized as content. Each resource may be described in a <resource> element within a manifest's XML. This element includes a list of all the assets required to use the resource. The files included in the Package are listed as <file> elements within such <resource> elements.
2.2 Standard Name for the Manifest File
Content distributed according to the 1EdTech Content Packaging specification must contain an 1EdTech Manifest file. To ensure that the 1EdTech Manifest file can always be found within a Package, it has a pre-defined name and location:
In the absence of this file, the package is not an 1EdTech Package and cannot be processed. It is required that the name be kept, as above, in all lowercase letters.
The 1EdTech Manifest file and any of its directly referenced XML control files (DTD, XSD) must be placed at the root of the Package Interchange File or any other packaging image (like a CD-ROM). XML control files that are indirectly referenced can be located as required by the namespace and path names. The usage of remote or local validation files is implementation dependent.
However, if local files are used then these must be identical to those online. If "local" validation is going to be performed using a local copy of the W3C xml.xsd and the validation process is going to be done in a "disconnected" environment, then "local" versions (i.e., copy of) of the following files will also be needed: datatypes.dtd and XMLSchema.dtd. These DTDs are used by the W3C provided xml.xsd and can be obtained from the W3C.
3. Extensibility
An important underpinning of the 1EdTech Content Packaging specification is rich support for extensibility.
While the base Content Packaging Information Model leverages the rich set of meta-data elements defined in the 1EdTech Meta-Data Specification v1.2.1 or the IEEE 1484.12.3 Standard for eXtensible Markup Language (XML) Schema Binding for Learning Object Metadata (see 1EdTech Meta-Data v1.3 [MD, 04] for best practices and guidelines in implementing the IEEE LOM specification), it defines only the basic structures for organization and resources (Web Content).
It is expected that implementers of this specification will define new types of resources and organizations to describe and transport rich learning resources, and over time, it may be possible to incorporate widely used extensions into future versions of this specification.
4. Manifest Elements
This section provides a conceptual, informative description of the elements contained in a Manifest. Figure 4.1 illustrates the primary elements of a Manifest.
Table 4.1 provides a conceptual, informative description of the data objects. The columns used in the table refer to:
Notes: Additional descriptive information about the element.
- In the table below, the Manifest elements contained in the Content Packaging Information Model are described using mixed case to enhance readability. Implementers of this specification should refer to particular binding specifications. For example, some XML bindings follow the W3C convention of using lowercase for all elements;
- Elements surrounded by braces ({}) indicate areas in the Information Model where elements from other information models or specifications are expected to be included;
- The order of elements described in Table 4.1 is not significant from the perspective of the information model. However, the corresponding XML binding imposes this implied order as a requirement for 1EdTech manifests.
4.1 sub-Manifests
When the identifierref of an <item> in an <organization> references a sub-Manifest rather than another type of resource, this shall be interpreted as follows:
- If the sub-Manifest does not include any <organization>, the reference cannot be resolved. This shall be treated as a null identifierref;
- If the sub-Manifest includes an <organization>, the root node of that organization (i.e., the <organization> element itself) shall merge with the <item> that references the sub-Manifest. If the same attribute is specified for both the <item> and the <organization> it references, but with different values, the value defined for the referred <organization> manifest shall override the value defined for the referring <item>. That is, child attributes take precedence over parent attributes. This behavior is expected of the rendering of the navigation tree, but does not need to affect the XML of the manifest(s).
The diagram in Figure 4.2 explains how the content of a sub-Manifest is merged with the content of a referencing manifest in the rendering of a navigation tree. The circles represent items in an organization structure. In this example, the organization of the sub-manifest does not have a title attribute.
The diagram in Figure 4.3 shows an example where the <organization> of the sub-Manifest does have a title attribute.
In Figure 4.4, the diagram explains how the content of a sub-Manifest is merged with an item that has children of its own, and how the referencing item's children take precedence over those they merge with. In this example, the organization of the sub-Manifest does not have a title attribute.
4.2 Href URL Construction Algorithm
In the cases where full URL referenced in the 'Href' value is also based upon the parameters passed in the 'parameter' attribute of the <item> referencing the <resource> then the following algorithm is to be used to construct the full URL:
While first char of parameters is in"?&"
Clear first char of parameters
If first char of parameters is "#"
If the URI contains "#"
Discard parameters
Else
Append parameters to the URI
Done processing URI
If the URI contains "?"
Append "&" to the URI
Else
Append "?" to the URI
Append parameters to the URI
Done processing the URI
The definition of this algorithm is normative.
About This Document
| Title | 1EdTech Content Packaging Information Model |
| Editors | Colin Smythe (1EdTech), Alex Jackl (1EdTech) |
| Version | 1.1.4 |
| Version Date | 04 October 2004 |
| Status | Final Specification |
| Summary | This document describes the Content Packaging Information Model, which is used to support content interoperability between different authors, publishers, and other corresponding content developers. |
| Revision Information | 04 October 2004 |
| Purpose | This document has been approved by the 1EdTech Technical Board and is made available for adoption. |
| Document Location | http://www.imsglobal.org/content/packaging/cpv1p1p4/imscp_infov1p1p4.html |
| To register any comments or questions about this specification please visit: http://www.imsglobal.org/developers/ims/imsforum/categories.cfm?catid=5 |
List of Contributors
The following individuals contributed to the development of this document:
Revision History
Index
A
Aggregation 1
Attributes
default 1
href 1
isvisible 1
parameters 1
structure 1
type 1, 2
version 1
B
Behavior 1, 2
Best Practice Guide 1, 2, 3, 4, 5
Binding 1, 2, 3
C
Course
content 1
D
Disaggregation 1
E
Elements
file 1, 2
item 1
manifest 1, 2
organization 1
resource 1
resources 1
schema 1
title 1
Extensibility 1, 2
I
IEEE 1
1EdTech Specifications
Content Packaging 1, 2, 3, 4, 5
Learner Information Package 1
Meta-Data 1, 2, 3, 4
imsmanifest 1, 2
Information Model 1, 2, 3, 4
Interoperability 1
ISO 1, 2
L
Learning 1, 2, 3
LMS 1, 2
LOM 1
M
Manifest 1, 2, 3, 4, 5, 6, 7, 8
Meta-data 1, 2, 3, 4, 5
P
Package 1
Package Interchange File 1, 2, 3
PKZip 1
R
Resource 1, 2, 3, 4, 5, 6, 7
Resources 1, 2, 3, 4, 5, 6, 7
RFC 1
S
Schema 1, 2
Structure 1, 2, 3
sub-Manifest 1, 2, 3, 4, 5, 6
U
URI 1
X
XML 1, 2, 3, 4, 5, 6, 7
XSD 1, 2, 3, 4
1EdTech Consortium, Inc. ("1EdTech") is publishing the information contained in this 1EdTech Content Packaging Information Model ("Specification") for purposes of scientific, experimental, and scholarly collaboration only.
1EdTech makes no warranty or representation regarding the accuracy or completeness of the Specification.
This material is provided on an "As Is" and "As Available" basis.
The Specification is at all times subject to change and revision without notice.
It is your sole responsibility to evaluate the usefulness, accuracy, and completeness of the Specification as it relates to you.
1EdTech would appreciate receiving your comments and suggestions.
Please contact 1EdTech through our website at http://www.imsglobal.org
Please refer to Document Name: 1EdTech Content Packaging Information Model Revision: 04 October 2004
