laos: layered www ahs authoring model and their corresponding algebraic operators
DESCRIPTION
LAOS: Layered WWW AHS Authoring Model and their corresponding Algebraic Operators. Dr. Alexandra Cristea [email protected] http://www.dcs.warwick.ac.uk/~acristea/. LAOS. What is LAOS? Concept based adaptation LAOS components Why LAOS? LAOS authoring steps Future directions. - PowerPoint PPT PresentationTRANSCRIPT
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
Invited Tutorial, Madrid, Spain April 2008
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
Invited Tutorial, Madrid, Spain April 2008
General motivation for layer distributed information
• Flexibility• Expressivity (semantics: also meta-data)• Reusability• Non-redundancy• Cooperation• Inter-operability • Standardization
Invited Tutorial, Madrid, Spain April 2008
LAOS components
• domain model (DM),
• goal and constraints model (GM),
• user model (UM),
• adaptation model (AM) and
• presentation model (PM)
Invited Tutorial, Madrid, Spain April 2008
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)?
Invited Tutorial, Madrid, Spain April 2008
LAOS motivation in detail
• Why domain model (DM) ?
• Because of historical AHS, ITS, AHAM
• Why goal and constraints model (GM)?
• Why user model (UM)?
• Why adaptation model (AM)? and
• Why presentation model (PM)?
Invited Tutorial, Madrid, Spain April 2008
LAOS motivation in detail
• Why domain model (DM) ?
• Why goal and constraints model (GM)?
• Why user model (UM)?
• Because of historical ITS, AHS, AHAM
• Why adaptation model (AM)? and
• Why presentation model (PM)?
Invited Tutorial, Madrid, Spain April 2008
LAOS motivation in detail
• Why domain model (DM) ?
• Why goal and constraints model (GM)?
• Why user model (UM)?
• Why adaptation model (AM)? and
• Because of AHAM – see also LAG !!
• Why presentation model (PM)?
Invited Tutorial, Madrid, Spain April 2008
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 Kuypers, AHAM
Invited Tutorial, Madrid, Spain April 2008
LAOS motivation in detail
• Why domain model (DM) ?
• Why goal and constraints model (GM)?
• Because of book metaphor• Also because of goal adaptation!!
(see adapt to what?)
• Why user model (UM)?
• Why adaptation model (AM)? and
• Why presentation model (PM)?
Invited Tutorial, Madrid, Spain April 2008
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
Invited Tutorial, Madrid, Spain April 2008
GM motivation
• intermediate authoring step,
• goal & constraints related:
• goals: focused presentation– specific end-state
• constraints: limit search space– DM filter
Invited Tutorial, Madrid, Spain April 2008
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)
Invited Tutorial, Madrid, Spain April 2008
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.
Invited Tutorial, Madrid, Spain April 2008
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.
Invited Tutorial, Madrid, Spain April 2008
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.
Invited Tutorial, Madrid, Spain April 2008
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)
Invited Tutorial, Madrid, Spain April 2008
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
Invited Tutorial, Madrid, Spain April 2008
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
Invited Tutorial, Madrid, Spain April 2008
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
Invited Tutorial, Madrid, Spain April 2008
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.
Invited Tutorial, Madrid, Spain April 2008
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
Invited Tutorial, Madrid, Spain April 2008
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
Invited Tutorial, Madrid, Spain April 2008
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)
Invited Tutorial, Madrid, Spain April 2008
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
Invited Tutorial, Madrid, Spain April 2008
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
Invited Tutorial, Madrid, Spain April 2008
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).