Sharable Content Object Reference Model

Draft

Definition

• SCORM is a sort of "standards package" (also called "profile" or "collection of standards") promoted by the Advanced Distributed Learning (ADL) initiative by the US government, i.e. the Department of Defense (DOD). However, SCORM is also a de facto Industry Standard.

• The Sharable Content Object Reference Model (SCORM) specifies how learning content should be coded, how others can later "discover" that content, how it fits into a sequence of learning activities, and how its appearance through the delivery media can be customized for the individual learner.

• Here is another quote from their Web Site (feb 2006): "The Sharable Content Object Reference Model (SCORM) defines a Web-based learning "Content Aggregation Model" and "Run-Time Environment" for learning objects. At its simplest, it is a reference model that references a set of interrelated technical specifications and guidelines designed to meet DoD's high level requirements for Web-based learning content. These requirements include, but are not limited to, reusability, accessibility, durability and interoperability."

• Until 2000 SCORM was an acronym for "Sharable Courseware Object Reference Model".

See also:

• learning objects for a general discussion on modular, reusable learning contents and activities.
• SCORM 1.2 for a more in-depth discussion of the most popular SCORM profile

Contents of the SCORM profiles

It is quite difficult to find out which different standards (e.g. form IMS) are integrated in which SCORM profile. It is even more difficult to understand how additions by SCORM fit in.

Versions

SCORM 1.0 (January 2000)

The original version of SCORM was primarily a test version. The concept of a Sharable Content Object (SCO) was introduced and after some testing, ADL made some implementation examples available.

SCORM 1.1 (January 2001)

This profile marked the end of a first trial and error implementation phase and the beginning of the application phase. This version used a XML file based on AICC specifications for describing content structure. Also noteworthy is the change from Sharable Courseware Object Reference Model to Sharable Content Object Reference Model. This version, though improved still lacked support for metadata and was quickly replaced by SCORM 1.2.

SCORM 1.2 (October 2001)

The most important parts of this profile are the Run-Time Environment (RTE) and Content Aggregation Model (CAM).

• The RTE specifies how content should behave once it has been launched by the LMS.
• The CAM specifies how you should package your content so that it can be imported into an LMS. This involves creating XML files that an LMS can read and learn everything it needs about metadata describing the course, its pedagogical content elements and organization of the learning experience. To that purpopose SCORM adapted the IMS Content Packaging specification and the IMS Learning Resource Meta-data Specification which slightly modified became the IMS/IEEE Learning Object Metadata Standard.

SCORM 1.2 remains the most popular standard industry, although it is now replaced by SCORM SCORM 2004 (initially called Scorm 1.3).

Important Note: An SCORM Content Package is not the same as a standard IMS Content Package. It may include XML tags for AICC sequencing and JavaScript calls to the LMS (according to AICC/CMI Guidelines for Interoperability which later in modified form became an IEEE standard).

SCORM 2004

January 2004. The current version adds:

• IEEE’s ECMAScript Application Programming Interface. More particularly: Content to Learning Management System (LMS) communication and Data model for content to LMS communication
• It adopts IMS Simple Sequencing, i.e. the possibility to define learning sequences depending on the sequence of activities. It also allows for a sharing and use of information on learners status with respect to the learning objectives and competencies acquired while working through different content objects and courses, so long as they remain within the same LMS.

This more robust version should offer greater interoperability since it adopts "stronger" IEEE API and IMS sequencing standards.

SCORM 1.2

It used to be difficult to find mostly SCORM-conformant LMS besides the [1] list of SCORM certified products. Many open source system claim to be SCORM conformant, but DSchneider is not sure of this.

A SCORM compliant system must adopt the Content Aggregation Model (CAM) and the Run-Time Environment (RTE)

The Run-Time Environment

The API

According to Rustici (2004), a SCORM conformant LMS is required to implement an API, i.e. a ECAMAScript object named "API" accessible through the DOM and that implements eight JavaScript functions.

Functions for execution state

LMSInitialize()
LMSFinish()

Functions for data transfer

LMSGetValue()
LMSSetValue()
LMSCommit()

Functions for error handling

LMSGetLastError()
LMSGetErrorString()
LMSGetDiagnostic()

'All' communication between the content and the LMS is handled by this adapter.

For minimal SCORM conformance, the only thing that a piece of content needs to do is call LMSInitialize() when it starts and then call LMSFinish() when it exits.

The CMI Data Model

SCORM adopts the "cmi" data model from AICC. It consists of data model elements which the content can read from and write to using this interface. Here is an example from Rustici (2004):

cmi.core.lesson_location is the data element that describes the user's location in the content.

When the content begins (after it has called LMSInitialize();), it may want to make this call to find out where the user left off and return him to that point:

strLastLocation = objAPI.LMSGetValue("cmi.core.lesson_location");

The Data Model describes several kinds of data. The following table lists some of these data types plus associated JavaScript objects and some possible system messages displayed to the user.

• Mode (cmi.core.lesson_mode), e.g. 'normal', 'review', 'browse'.
• Status (cmi.core.lesson_status and cmi.objectives.n.status), e.g 'completed', 'failed', 'passed', 'incomplete', 'browsed', 'not attempted'.
• Exit (cmi.core.exit), e.g. 'time-out', 'suspend', 'logout'
• Credit (cmi.core.credit), e.g. 'credit', 'no-credit'
• Entry (cmi.core.entry), e.g. 'resume', 'ab-initio'
• Interaction (cmi.interactions.n.type), e.g. 'choice', 'true-false', 'fill-in', 'matching', "performance", "likert", "sequencing", "numeric"
• Result (cmi.interactions.n.result), e.g. 'wrong','unanticipated', 'neutral', X.X (CMIDecimal)
• Time Limit Action (cmi.student_data.time_limit_action) 'exit,no message', 'exit,message', 'continue,message', 'continue,no message'

Here are a few more data types, this time with a short explanation of the purpose ):

cmi.core.student_id	Unique alpha-numeric code / identifier that refers to a single user of the LMS system.
cmi.core.lesson_location	This corresponds to the SCO exit point passed to the LMS system the last time the student experienced the SCO. This provides one mechanism to let the student return to a SCO at the same place he left it earlier. In other words, this element can identify the student's exit point and that exit point can be used by the SCO as an entry point the next time the student runs the SCO.
cmi.core.score.raw	Indication of the performance of the student during his last attempt on the SCO. This score may be determined and calculated in any manner that makes sense to the SCO designer.
cmi.interactions.n.type	Indication of which category of interaction is recorded. The type of interaction determines how the interaction response should be interpreted, e.g. "true-false", "choice", "fill-in", etc.

Please read the 40 pages of definitions in the The SCORM Run-Time Environment manual for real information. The examples above are here to give a feeling of CMI Data Model's expressive power.

The Content Aggregation Model and Structure

This model includes three standards:

• IMS Content Packaging (CP) with 'extensions'.
• IMS Meta Data (i.e. an older version of the IEEE Learning Object Metadata Standard)
• Sharable Content Objects (SCOs). These are special kinds of resources used in an IMS content package (CP). The structure of the resource part of the CP is exactly the same as in a "simple" IMS content pack. However SCO's do communicate with the LMS, while an 'asset is a simple content that is just "played".

SCORM Content Aggregation with Assets and SCO, picture taken from a SCORM manual, reproduced without special permission.

According to the The SCORM Content Aggregation Model manual, {{quotation | The purpose of content structure is to provide the content developer with the means to author collections of learning resources into a cohesive unit of instruction, apply structure and associate specific behaviors that can be uniformly reproduced across LMS environments. The content structure can be considered the map used to sequence/navigate through the learning resources defined in the content package. The content structure contains not only the structure of the learning resources, but also all behaviors to be applied to the learning experience.

SCORM extends the simple IMS Content Pack default organisation inclusion not only with SCOs, but also with a subset of additional vocabulary to define learning sequences and that are derived from the Aviation Industry Computer-Based Training Committee (AICC) Computer Managed Instruction.

Roughly, a SCORM Manifest looks like this:

<manifest identifier=\u201dManifest" version="1.1"
  xmlns="http://www.imsproject.org/xsd/imscp_rootv1p1p2"
  xmlns:adlcp="http://www.adlnet.org/xsd/adl_cp_rootv1p1"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.imsproject.org/xsd/imscp_rootv1p1p2
                  imscp_rootv1p1p2.xsd
                  http://www.imsproject.org/xsd/imsmd_rootv1p2
                  ims_md_rootv1p1.xsd
                  http://www.adlnet.org/xsd/adl_cp_rootv1p1
                  adl_cp_rootv1p1.xsd">

 <metadata>
   <schema>ADL SCORM</schema>
   <schemaversion>1.2</schemaversion>
   <imsmd:lom>
      <imsmd:general>
         <imsmd:title>
             <imsmd:langstring xml:lang="en-US">Example Manifest</imsmd:langstring>
         </imsmd:title>
      </imsmd:general>
  </imsmd:lom>
 </metadata>

 <organizations default="TOC1">
    <organization identifier="TOC1" structure="hierarchical">
       <title>default</title>
       <item identifier="ITEM1" identifierref="RESOURCE1" isvisible="true">
          <title>Lesson 1</title>
             <item identifier="ITEM2" identifierref="RESOURCE2" isvisible="true">
             <title>Introduction 1</title>
          </item>
       <item identifier="ITEM3" identifierref="RESOURCE3" isvisible="true">
            <title>Content 1</title>
         </item>
         <item identifier="ITEM4" identifierref="RESOURCE4" isvisible="true">
            <title>Summary 1</title>
         </item>
      </item>
    <item identifier="ITEM5" identifierref="RESOURCE5" isvisible="false">
  ....
  </organization>
 </organizations>

 <resources>
    <resource identifier="RESOURCE1"
       <file href="lesson1.htm"/>
    </resource>
    <resource identifier="RESOURCE2"
       <file href="intro1.htm"/>
    </resource>
 ...
 </resources>

</manifest>

Sequencing and navigation

Sequencing and navigation behavior refers to the rules that an LMS must follow in order to present a specific learning experience. These rules encoded in the organization section of Content Packaging. The main different form the default IMS Content Pack lies in the definition of the item element.

Prerequisite scripting

This article or section is currently under construction

In principle, someone is working on it and there should be a better version in a not so distant future.
If you want to modify this page, please discuss it with the person working on it (see the "history")

Organization items can contain SCORM extensions that define operators of a prerequisite scripting language called aicc_script. These are based on the AICC CMI001 Guidelines for Interoperability.

An example: The following means that in order to access item I3, the learner must pass items I1 and I2.

<item identifier='I0'>
  <item identifier='I1' identifierref='R_I1'>
  <item identifier='I2' identifierref='R_I2'>
  <item identifier='I3' identifierref='R_I3'>
     <adlcp:prerequisites type='aicc_script'>
        I1&I2</adlcp:prerequisites>
  </item>
</item>

Operators

(see page 2-109 of the manual)

Comment

While SCORM represents today's main-stream e-learning that is focused on delivery of courseware it does not represent in our opinion all of what educational technology can be. The main long-term contribution of SCORM was its insistence on data standards, run-time standards (i.e. interoperability) which indeed are major issue for organizations like the US Department of Defense that sponsors over 30'000 training courses. Frustration over non existing standards also led industry and even parts of Academia to adopt various SCORM profiles.

Tools

There are a number of tools that allow you to edit Scorm 1.2 or 1.3 compatible contents, e.g here are 2 free ones:

• Reload Editor - (Reload Scorm Editor home page). It is not easy to author SCO's with that !
• eXe

However, be warned about "SCORM-compatible" LMS. Full SCORM compatibility is not guaranteed even if your vendor says so. E.g. your LMS may well play contents, but not be able to provide user tracking. Only trust certified software by ADL or those you tested...

Links

Standards and Bodies

• Advanced Distributed Learning, home of SCORM.
• IEEE Learning Technology Standards Committee. Mandated to "develop accredited technical standards, recommended practices, and guides for learning technology" (from their new website)

Introductions

• SCORM Course from JCA Solutions
• SCORM Overview by Randall House Associates

References

• Rustici, Mike (2004). Two Minute SCORM Overview for Developers. ADL Website, , retrieved 18:05, 18 December 2006 (MET). (This is a must read !)

• Advanced Distributed Learning Initiative, Sharable Content Object Reference Model (SCORM), Version 1.2, The SCORM Run-Time, Environment, October 1, 2001 (available from ADL

• Advanced Distributed Learning Initiative, Sharable Content Object Reference Model (SCORM), Version 1.2, The SCORM Content Aggregation Model, October 1, 2001 (available from ADL