Maurice Hendrix, Alexandra Cristea CATE 2008

maurice@dcs.warwick.ac.ukhttp://www.dcs.warwick.ac.uk/~maurice

A meta level for LAG Adaptation Language re-use in education

Outline• LAOS• Limitations of LAG• Solution• Proposed extension• System setup of extension

LAOS 5 layer model for AH authoring:

• Domain model (DM)• Goal and constraints model (GM)• Adaptation model (AM)• User models (UM)• Presentation model (PM)

AH Authoring: LAOS

Authoring now: DM & GM• Several tools like MOT (My Online

Teacher)• Efforts to automate part of the process• Can easily be done by teachers without

CS background• Content can be reused and transported

easily e.g. via CAF and (recently) e-learning standards

Example DM authoring

Authoring AM• Either pre-prepared strategy or

programming knowledge required

• Re-use possible, but not very flexible, (DM/GM needs to be set-up for specific strategy)

• In LAOS AM is authored using LAG, programming language like

Example AM authoring (LAG Language)initialization( PM.next = true PM.ToDo = false PM.menu = true while true ( PM.GM.Concept.show = true UM.GM.Concept.beenthere = 0 ) UM.GM.begnum = 0 UM.GM.intnum = 0….

Limitations of LAG

• Inherent run-time limitations.• No access to all items during run-time• Thus no Access to set of metadata (labels and weights) and concepts in use• Combined strategies have to share metadata fields

Examples of Limitations

• Beginner – Intermediate – Advanced type strategy with arbitrary knowledge level groups defined by authors metadata (weight & label).

• Course on general domain identifying the users more specific topic of interest using metadata (labels)

• Integration of multiple strategies (currently forced use of same metadata field is a problem)

Solution

• Access to the set of weights and labels (the metadata) at compile-time often enough

• Propose extension to LAG language to allow compile-time access to set of label/weights & regular expression matching as metadata share mechanism

Proposed extension

• XML format for the additions

• Easy to implement and maintain

• Can cope with changing LAG

• Adding like statement capturing labels with reg expr

DTD

<!ELEMENT CAF (LAGfragment*, LIKE*)*>

<!ELEMENT LIKE attribute CDATA value CDATA (LAGfragment, MATCH, LAGfragment+, (LAGfragment*, LABEL, LAGfragment*)*) >

<!ELEMENT LAGfragment (#PCDATA)><!ELEMENT MATCH EMPTY><!ELEMENT LABEL EMPTY>

Example

<like attribute='GM.Concept.label' value='beginner'>

while <match/> UM.GM.<label/>_number += 1 ) </like>

System setup of extension

Templated LAG processorTemplated LAG

Pre-processor

CAF

AHA! Lesson creationLAG AHA!

Lesson

Conclusion & Further work

• Using a simple pre-processing some limitations of LAG can be overcome

• Next in line is building a prototype, integrated with advancing LAG developments

• Conceptual Adaptation Model (CAM) of the Grapple project

Thank you for your attention

• Questions?