The SCORM Runtime Environment Chris Poole: Senior Content Developer The Scorm Runtime Environment An...

Chris Poole: Senior Content Developer

The SCORM Runtime EnvironmentThe SCORM Runtime Environment

The Scorm Runtime Environment

An Overview

By

Chris Poole



• The SCORM is based directly on the run-time environment functionality defined in AICC’s CMI001 Guidelines for Interoperability



• ADL collaborated with AICC members and participants to develop a common Launch and API specification and to adopt Web-based data elements



• One of the main goals of the SCORM is interoperable content

• This means we have a number of problems to solve– How does the LMS start the learning object– How does the LMS and learning object communicate– What language do they speak– What do they say



• To address these problems the runtime environment uses three components:– Launch– Application Program Interface (API)– Data Model



• The Launch Mechanism– Defines the procedures and responsibilities for

establishment of communication between the object and the LMS

– Standardises the communication protocols by the use of an API



• Launch– What can we launch?

• SCO’s

• Assets



• The LMS must– Launch the SCO in a browser window that is

• a child window or a child frame of the LMS window that exposes the API Adapter as a Document Object Model Object

– Provide the API Adapter



• The SCO must– Find the API Adapter

• recursively search the parent and/or opener window hierarchy

– Once the API Adapter has been found the SCO may initiate communication with the LMS



• Assets– The SCORM launch model only requires that an LMS

launch the Asset using the HTTP protocol– Since an Asset does not need to communicate with the

LMS there is no need for an Asset to search for the API Adapter



• Application Program Interface (API)– Communicates the state of the learning object to the LMS

• Initialised

• Finished

• In Error



• Why use an API?– Fulfills many of the SCORM’s high-level requirements for

interoperability and reuse– It provides a standardised way for SCOs to communicate

with LMSs– Shields the particular communication implementation from

the content developer



• What is it?– A set of predefined functions that the SCO can rely on being

available

– A piece of functional software that implements and exposes the functions of the API



• Why Use it?– An API hides implementation details from SCOs

– promotes reuse and interoperability

– Gives content developers a common public interface to any LMS



• The API is – a communication mechanism that allows the SCO to communicate

with the LMS

– Once the SCO is launched it can• “get” information from an LMS or• “set” information within an LMS• All communication is initiated by the SCO• No supported mechanism for LMSs to initiate calls to functions

implemented by a SCO



• The API Adapter object has three functions– Execution State

– State Management

– Data Transfer



• Execution State– API has two functions to handle execution state

• LMSInitialize(“”)• LMSFinish(“”),



• State Management– The API has three functions that are used to handle errors

• LMSGetLastError()

• LMSGetErrorString(errornumber)

• LMSGetDiagnostic(parameter).



• Data Transfer– The remaining API functions transfer data to and from an

LMS• LMSGetValue(data model element)

• LMSSetValue(data model elementvalue)

• LMSCommit("")



• State Management– The API has three functions that are used to handle errors


• LMSGetErrorString(errornumber)

• LMSGetDiagnostic(parameter).



• The API can be in on of three states– Not Initialised– Initialised– Finished



• A SCO can behave differently in each of these states

• Not Initialised– A SCO must

• find the API

• Call LMSInitialize(“”)



• Initialised– A SCO can

• LMSGetValue

• LMSSetValue

• LMSGetLastError

• LMSGetErrorString

• LMSGetDiagnostic

• LMSCommit

• LMSFinish



• Finished– The SCO can


• LMSGetErrorString()

• LMSGetDiagnostic()



• API General Rules– The function names are all case sensitive, and must always be

expressed exactly as shown

– The function parameters or arguments are case sensitive. All parameters are lower case.

– Each call to an API function, other than the error handling functions, resets the error code.



• The Data Model– A defined set of information that can be communicated.

What the SCO and LMS should know.• LMS must maintain the state of the data elements across

sessions.

• Learning content must only use the predefined data elements.



• So which Data Model do we use?– There are a number of data models under development in

various communities and standards organisations– These draft data model specifications attempt to functionally

group information sets to be exchanged between SCOs and LMS environments



• Examples include: – student profile information– question and test interactions– state information– assessment

• These draft data model sets are still under development and have not been widely implemented or tested



• The SCORM Run-Time Environment Data Model – derived directly from the AICC CMI Data Model described in

the AICC CMI Guidelines for Interoperability4



• It is expected that – In the future new data model sets will be adopted and

incorporated into the SCORM– the data model elements defined in this version of the

SCORM will map to new data model sets



• To identify the data model in use– Names of the elements start with “cmi”

• This signals implementers that these elements are part of the AICC CMI Data Model

– Alternative data models, as developed, will start with a different designation

• (e.g., adl.elementName instead of cmi.elementName)



• The AICC and IEEE decided to reduce the number of elements in the AICC CMI Data Model– to ease the transition to new data models under

development– many of the elements removed had not actually been

implemented by most implementers– A list of elements removed from the AICC CMI Data Model

that appeared in the SCORM Version 1.0 are summarized in Appendix C

– The SCORM Run-Time Environment Data Model matches the reduced AICC CMI Data Model set.



• The SCORM Run-Time Environment Data Model General Rules

– The first symbol in the data element name identifies the data model. For example, "cmi" indicates the AICC CMI Data Model. This expands the functionality of the API by allowing the same API to be used with other data models;



• There are three reserved keywords. These are all lower case and proceeded by an underscore

– _version: keyword used to determine the version of the data model supported by the LMS

– _children: keyword used to determine which data model elements are supported by the LMS

– _count: keyword used to determine the number of elements currently in a list



• All arrays are 0 based arrays– Items should be placed in the arrays in a sequential manner

• The data model names are case sensitive• The data model is implemented on a SCO by

SCO basis– One SCO cannot access another SCO’s data elements



• Dreamweaver Course Builder Interactions– Claim to be AICC compliant

• Objects do try to connect to tracking system

• Objects do use cmi data model elements

• Objects do provide good interactive functionality

BUT– Elements are not referenced using the SCORM rules



• Coding (how DW tracking works) G01.am('segm','Segment: Correctness_',1,0); G01.am('cond','Correct_01','G01.correct == true',0); G01.am('actn','Popup essage','MM_popupMsg(\'Correct\')',''); G01.am('end'); G01.am('cond','Incorrect_','G01.correct == (false)',0); G01.am('actn','Popup

Message','MM_popupMsg(\'Incorrect\')',''); G01.am('end');



• Dreamweaver SCORM wrapper– Allows for the insertion of code to minimum SCORM

conformancefunction mm_adlOnload(){ if (mm_adl_API != null) { mm_adl_API.LMSInitialize(""); // set status mm_adl_API.LMSSetValue("cmi.core.lesson_status",

"incomplete"); }}



• Conclusions– Launch

• Defines a common method for launching SCO’s and Assets

– The API • shields developer from LMS implementation• Performs data transfer from SCO to LMS• Performs state management

– The Data Model• Based on AICC cmi data model• Is designed to allow development and inclusion of new data

models



• Further Research / Development Work– Understand AICC cmi data model elements and how they

can be used– Develop range of templates for

• SCO’s

• Assets

• A range of interactions

– That use the cmi data model elements in the SCORM format

The SCORM Runtime Environment Chris Poole: Senior Content Developer The Scorm Runtime Environment An...

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