laos: layered www ahs authoring model and their corresponding algebraic operators

LAOS:Layered WWW AHS Authoring Model

and their corresponding Algebraic Operators

Dr. Alexandra [email protected]

http://www.dcs.warwick.ac.uk/~acristea/

Invited Tutorial, Madrid, Spain April 2008

LAOS

1. What is LAOS?2. Concept based adaptation3. LAOS components4. Why LAOS?5. LAOS authoring steps6. Future directions


What is LAOS?


What is LAOS ?

• a generalized model for generic adaptive hypermedia authoring

• based on the AHAM model• based on concept maps

• http://wwwis.win.tue.nl/~alex/HTML/Minerva/papers/http://wwwis.win.tue.nl/~alex/HTML/Minerva/papers/WWW03-cristea-WWW03-cristea-mooij.docmooij.doc

• http://www.ifets.info/journals/7_4/7.pdfhttp://www.ifets.info/journals/7_4/7.pdf


Why LAOS?


General motivation for layer distributed information

• Flexibility• Expressivity (semantics: also meta-data)• Reusability• Non-redundancy• Cooperation• Inter-operability • Standardization


LAOS components


LAOS components

• domain model (DM),

• goal and constraints model (GM),

• user model (UM),

• adaptation model (AM) and

• presentation model (PM)


LAOS motivation in detail

• Why domain model (DM) ?

• Why goal and constraints model (GM)?

• Why user model (UM)?

• Why adaptation model (AM)? and

• Why presentation model (PM)?




• Because of historical AHS, ITS, AHAM










• Because of historical ITS, AHS, AHAM









• Because of AHAM – see also LAG !!









• Because of Kuypers, AHAM





• Because of book metaphor• Also because of goal adaptation!!

(see adapt to what?)





GM book metaphor – why?

• Domain model: – equivalent to skip the presentation and just

tell the user to read the book.

• search space too big • Not only one purposeful orientation


GM motivation

• intermediate authoring step,

• goal & constraints related:

• goals: focused presentation– specific end-state

• constraints: limit search space– DM filter


DM


GM


Authoring steps in LAOS• STEP 1: write domain concepts + concept hierarchy + attributes

(contents) + other domaindomain relations• STEP 2: add content related adaptive features regarding GMGM

(design alternatives – AND, OR, weights, etc.)• STEP 3: add UMUM related features (simplest way, tables, with

attribute-value pairs for user-related entities (AHAM); UM can be represented as a concept map)

• STEP 4: decide among adaptationadaptation strategies, write in adaptation language medium-level adaptation rules or give the complete set of low level rules (such as condition-action (CA) or IF-THEN rules).

• STEP 5: define format (presentationpresentation means-related; define chapters)


LAOS components – definitions


Domain concept model• Definition 1. An AHS domain map DM is determined

by the tuple <C,L, Att>, – where C: set of concepts, – L: set of links,– Att a set of DM attributes

• Definition 2. A domain concept cDMi. C is defined by <A,C> – where A : set of attrs and C : set of sub-concepts.

• Constraint 1. Amin is the minimal set of (standard) attributes required for each concept to have (AAmin).– for sufficient meta-data– if Amin = required standard attributes.


Domain concept model – cont.

• Definition range 2.1. A domain concept cC is a composite domain conceptcomposite domain concept if c.C.

• Definition range 2.2. A concept cC is an atomic atomic domain conceptdomain concept if c.C=.

• Definition 3. A domaindomain linklink lL is a tuple <S, E, N, W> with S,E {DMi.ck}i,k (S, E) start and end sets of DM concept instances, respectively; N set of labels of the links; W set of weights of the links.


Domain concept model – cont.

• Definition 4. A domain attribute a DMi.C.A is a tuple <type, val>, where – type is the name of the DM attribute; – val is the value (contents) of the DM attribute.

• Constraint 2. concept c must be involved at least in one link l. This special relation is called hierarchical link (link to ancestor concept). Exception: root concept.


algebraic operators & respective operations over the model

• constructors – create, edit

• destructors – delete

• visualization or extractors– list, view, check

• compositors – repeat

•Effects

–restructuring (constructors, destructors and any compositors using at least one operator belonging to the previous categories) or

–structure neutral (visualization and any compositors applied to visualization alone)


operation &

operator

Range of operation in DM Description

Create&

‘C’

• Input (atomic): optionally object name (text label) of objects such as for DMx,; father concept for c; ids

(numerical) of (S, E) and labels, weights for l, ai[h] (with h>Amin )

Input (set): as above for sets of objects {cj}

+,{lj}+,{ai[h]}+ (with

1hAmin ) Output space: DM, C, L, A Output: DMx , {cj}

*,{lj}*,

{ai[h].type}*

creates one object such as a concept map, concept, link, a non-standard attribute creates sets of objects such as set of new hierarchical child nodes and/ or links connected to the same parent or a full standard attributes set


Edit&

‘E’

Input: object ids or expression Output: { {DMx, c, l, ai[h]}.type}*

edits the object value

Delete&

‘D’

Input: as the two above together, condition or expression

Output space: DM, C, L, A

deletes an object (set) from the corresponding structure or empties the contents


List&

‘L’

Input: Any sets from above, optional condition or expression Output: interface object

lists the objects of the set(s)

View&

‘V’

Input: (set of) object id-s and mode (e.g., Graph/ Text) Output: interface object

gives alternative views of the results to the author

Check&

‘Ck’

Input: (set of) object id-s from DM, C, L, A , checking goal, (and implicitly their value domains) Output: interface object

checks the checking goal for the selected object and informs about value domain trespasses

Repeat&

‘R’

Input: Any of above, number of times or other stopping condition Output space: same as operation performed

Repeats any of the operations above


Goal and constraints model

• Definition 5. A constraint conceptconstraint concept gGMi.G in GM is defined by the tuple <GA, G, DMj.c.a> GA is a set of attributes; G a set of sub-concepts; DMj.cC is the ancestor DM concept and DMj.c.aA is an attribute of that concept; GMi is the name of the GM map instance to whom it belongs.

• Definition 6. A constraint linkconstraint link glL is a tuple <S, E, N, W> with S,E {DMi.ck}i,k (S, E) start and end sets of GM concept instances, respectively; N set of labels of the links; W set of weights of the links.


Description

Create&

‘C’

Atomic operation

& operators

Range of operation in GM

Input: original concept id in GM and attribute id; optionally object name (text label) of objects such as for GMx, father concept for c; ids (numeric) of (S, E); labels, weightsfor l Input: as above for sets of objects {cj}

+,{lj}+,{ai[h].var}+ (1h2 ) Output space: GM , G, L, A Output: GMx, {cj}

*,{lj}*, {ai[h].type}*

creates object e.g. GM map, concept, link, a non-standard attribute creates sets of objects e.g., set of new hierarchical child nodes +/- links to the same parent or a full standard attributes set

Edit&

‘E’

Input: object ids or expression Output: { {GMx, c, l, ai[h]}.val}*

edits the object value

Delete&

‘D’

Input: as the two above together, condition or expression Output space: GM, G, L, A

deletes an object (set) from the corresponding structure or empties the contents


List&

‘L’

Input: Any sets from above, optional condition or expression Output: interface object

lists the objects of the set(s)

View&

‘V’

Input: (set of) object id-s and mode (e.g., Graph/ Text) Output: interface object

gives alternative views of the results to the author

Check&

‘Ck’

Input: (set of) object id-s from GM, G, L, Ac , checking goal, (and implicitly their value domains) Output: interface object

checks the checking goal for the selected object and informs about value domain trespasses

Repeat&

‘R’

Input: Any of above, number of times or other stopping condition Output space: same as operation performed

Repeats any of the operations above


What can LAOS do for you?


Example 1: flexibility index between concept C1 and rest of concepts in DM for automatic semantic

linking in the DM or GM

min2 1 )1()(,*)1( ACcardflexC

j cjc AA

where C = card(DM)and Amin = card(Amin)


Example 2: flexibility degree for selecting attributes from DM concept C1 for GM, considering the order

min

minc

min

min

min

A

cA

A

i

A

i

card

i

iA

A

iAPicardPflex

1

1

)(

1 1

)!(

!

),()),(()1( 1


Future developments LAOS


Future developments LAOS

• Operators for each layer (partially done)

• Automatic transformations between layers for authoring simplification (partially done)

• Automatic concept linking (partially done)

• Verification work of the different layers


LAOS summary

• a five level AHS authoring model with a clear cut separation of the processing levels:

• 1. the domain model (DM), • 2. the goal and constraint model (GM), • 3. the user model (UM), • 4. the adaptation model (AM) - more LAG

following • 5. the presentation model (PM).


Any questions?

laos: layered www ahs authoring model and their corresponding algebraic operators

Documents

generalized model

user model um

constraints model gm

detailwhy domain model

ahamwhy adaptation model

goal adaptation

goal constraints

domain relationsstep