A Model Based on Semantic Nets to Support Evolutionary and Adaptive Hypermedia Systems N. Padilla Zea M. Medina Medina M. J. Cabrera F. Molina Ortiz L. García Cabrera GEDES - UGR Laboratorio de Investigación en Videojuegos y E-Learning

Summary Introduction SEM-HP Results Conclusions and further work Laboratorio de Investigación en Videojuegos y E-Learning

Introduction AHS (Student perspective) Laboratorio de Investigación en Videojuegos y E-Learning Associative retrieval of information Diversity of formats Several ways to access information Adjust to users needs Reduce desorientation Reduce knowledge overloading Changes not on users demand Force to read prerrequisites Users should have control over when and how adapt Allow different types of navigation

Introduction AHS (Author perspective) Laboratorio de Investigación en Videojuegos y E-Learning Building more complex than non- adaptive systems Provide author tools Life cycle is not given importance enough Provide mechanisms to make changes easier and consistent SEM-HP (SEMantic, Systemic and Evolutionary model to develop HyPermedia Systems)

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning Design and development based on a cognitive model Development, maintenance and navigation easier and flexible Design in four phases to separate domain modelling, presentation, navigation and adaptation

Three elements to develop AHS -Development process - Architecture - Author tool SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning Divide-and-conquer strategy Guidelines regarding Soft. Eng. Four phases: 1.Memorization 2.Presentation 3.Navigation 4.Learning

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning The author specifies: –Information domain Set of items associated to concepts in the concept domain –Underlying conceptual domain To make semantic relations explicit Concepts to classify information items Concept: Idea, though or abstraction

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning The author selects different presentations or views of the knowledge domain obtained in the memorization phase

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning The author establishes how the user can navigate the available information items

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning Question about adaptation: What, who, how and when to adapt The author established mechanism to allow system to adjust to users characteristics and interests

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning These phases are iterative Evolutionary development because phases are able to integrate changes

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning Vertical division –4 related subsystems Horizontal division –2 layers for each subsystem System : Representation models designed during each development phase Meta-system: Evolutionary mechanisms to integrate and propagate changes –Evolutionary actions –Restrictions –Change propagation

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning Action 1 Action 2. Action n System restrictions? Author restrictions? To build and modify the HS… OK. I have finished Changes in other elements are needed? (Internal propagarion) Changes in other sybsystems are needed? (External propagarion)

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning Stores, structures and maintains conceptual and informational domain Catalogues information item on the underlying conceptual domain The representation model is a conceptual structure –Semantic net –2 types of nodes semantically tagged (concepts and information item) –Formal definition CS=(C, I, Rc, Rf, Ac, Af) Lets talk about vertical division… C: ConceptsRf: Functional Relations I: ItemsAc: Conceptual Associations Rc: Conceptual Relations Af: functional Relations

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning CS=(C, I, Rc, Rf, Ac, Af) Rc (Conceptual Relation) r c Rc is the tag placed in the arc joining c o C and c d C Ac ( Conceptual Association ) a c Ac is composed by 2 concepts and a r c that exists between them Rf (Functional Relation) r f Rf tags a link between i j I and c k C. Denotes the role that i j performs regarding c k Af (Functional Association) a f Rf is composed by a concept, an item and a r f Rf that exist between them

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning Each presentation of the conceptual and informational domain is a Conceptual Structure of Presentation Each presentation updates modifications performed in the Memorization Subsystem

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning Define rules Ro to navigate based on: – Last item accessed – Concept associated to this item – Concepts available from this one When a concept or item is deleted the meta-system propagates the change Deletes rules or predicates in rules

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning Models the user and adapts the system to his characteristics. Information at User model: Personal data Knowledge state Experience on subject Navigation experience Preferences Interests Goals

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning MEMORIZATION

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning PRESENTATION

SEM-HP Laboratorio de Investigación en Videojuegos y E-Learning LEARNING

Results Laboratorio de Investigación en Videojuegos y E-Learning 31 students Knowledge domain: Object Oriented Programmation JSEM-HP to build the HS Positive evaluation in 35 aspects Test by an opinion questionnaire

Results Laboratorio de Investigación en Videojuegos y E-Learning Usefulness of graphic browser of JSEM-HP (in the SEM-HP model the navigation is performed on the semantic net itself) 4.29/ 5 Usefulness of navigation on a partial view of the graph (the SEM-HP model provides the user with a different presentation depending on the knowledge subdomain in which the user is more interested) 4.06 / 5 Adaptation4.16 / 5 Efficiency of finding information through the browser on JSEM-HP against seeking information on the Web 3.8 / 5 Some results

Conclusions and further work Laboratorio de Investigación en Videojuegos y E-Learning SEM-HP is a semantic, systemic and evolutionary model to develop hypermedia systems Provides the author a systematic development process, a layered architecture and an author tool

Conclusions and further work Laboratorio de Investigación en Videojuegos y E-Learning The architecture is divide in 4 subsystems and has 2 abstraction levels to perform automatic evolution The navigation structure allows student to check their knowledge degree Finishing JSEM-HP to carry our wider assessments from students and author perspective

A Model Based on Semantic Nets to Support Evolutionary and Adaptive Hypermedia Systems N. Padilla Zea M. Medina Medina M. J. Cabrera F. Molina Ortiz L. García Cabrera GEDES - UGR Laboratorio de Investigación en Videojuegos y E-Learning THANK YOU!