Semantic Techniques for Enabling Knowledge Reuse in
Conceptual Modelling
Jorge Gracia, Jochem Liem, Esther Lozano, Oscar Corcho, Michal Trna, Asunción Gómez-Pérez, and Bert Bredeweg
Ontology Engineering Group, Universidad Politécnica de Madrid. Spain{jgracia, elozano, ocorcho, mtrna, asun}@fi.upm.es
Informatics Institute. University of Amsterdam. The Netherlands{j.liem, b.bredeweg}@uva.nl
ISWC, November 10th, Shanghai, China
Outline
2
1. Introduction
1. Qualitative Reasoning Modelling and Simulation
2. Application of Semantic Techniques
3. Existing approaches
2. Semantic Grounding
3. Ontology-Based Feedback
1. Types of feedback
2. Techniques of OBF
4. Some numbers
5. Conclusions
6. What’s going on...
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Introduction
• Conceptual representation of physical systems
• Prediction of the system behaviour through reasoning
• Simulation
• Qualitative (important landmarks no numerical details)
• Separation of structure and behaviour
• Multiple domains of application
• Environmental science• Physics• Economy• ...
3
Qualitative Reasoning
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Introduction
• Learning by modelling approach
• Learners formally express and test their conceptual knowledge about systems in an educational context
• Desirable features:– Shared learning environment, where
expert and learner models are uploaded
– Quality feedback extracted from the common knowledge
4
QR in science and education
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
QR Modelling and Simulation
5
Knowledge Representation
Entity hierarchy Scenario
Quantity: The dynamic aspects of the system
Influence: Natality determines δSize
Proportionality: δSize determines δNatality
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Semantic Techniques
• Bridging the gap between the loosely and imprecise terminology used by a learner and the well-defined semantics of an ontology
• Relating the QR models created by other learners or experts in order to automate the acquisition of feedback and recommendations
6
How semantic techniques could help?
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Semantic Techniques
7
DynaLearn
http://hcs.science.uva.nl/projects/DynaLearn/
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Semantic Techniques
8
Student
ModelGrounding
OWL exportSemantic repository
Quality feedback
Online ontologies
Modelling tool The Web
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Existing approaches
• QR modelling and simulation tools: Betty’s brain, Stella• Not grounding of terms to a common vocabulary• Not quality feedback from other models
• Conceptual modelling techniques: CmapTools• Concepts maps for knowledge representation• Collaborative use• No use of Semantic Web to maximize interoperability • Not common shared vocabularies
• Semantic techniques to enhance collaborative learning: DEPTH (Design Patterns Teaching Help System)
• Focused on software engineering education• Supports recommendation more rather than quality feedback
9
Related work
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Outline
10
1. Introduction
1. Qualitative Reasoning Modelling and Simulation
2. Application of Semantic Techniques
3. Existing approaches
2. Semantic Grounding
3. Ontology-Based Feedback
1. Types of feedback
2. Techniques of OBF
4. Some numbers
5. Conclusions
6. What’s going on...
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Semantic Grounding
11
http://dbpedia.org/resource/Mortality_ratehttp://dbpedia.org/resource/Population
http://www.anchorTerm.owl#NumberOf
Expert/teacher Student
grounding
Semantic repository
Anchor ontology
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Semantic Grounding
• Ensure lexical and semantic correctness of terms
• Ensure the interoperability among models
• Extraction of a common domain knowledge
• Detection of inconsistencies and contradictions between models
• Inference of new, non declared, knowledge
• Assist the model construction with feedback and recommendations
12
Benefits of grounding
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Outline
13
1. Introduction
1. Qualitative Reasoning Modelling and Simulation
2. Application of Semantic Techniques
3. Existing approaches
2. Semantic Grounding
3. Ontology-Based Feedback
1. Types of feedback
2. Techniques of OBF
4. Some numbers
5. Conclusions
6. What’s going on...
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Types of OBF
• Ontology matching based feedback• Improvements of terminology• Missing and extra terms in the learner model
− Missing hierarchical relations
• Semantic reasoning based feedback: Inconsistency between hierarchies of models
• Structure comparison based feedback: Differences between model structures
14Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Modules of OBF
15
Ontology Matching
Semantic Reasoner
Missing/ExtraOntology Elements
List of differences
Structure Comparison
Grounding-Based Alignment
Learner Model+
Reference Model
Inconsistency between Hierarchies
Differences between Model Structures
Improvement of Terminology
Preliminary mappings
List of equivalent terms
Grounding-Based Alignment
• In the learner model:
• In the reference model:
• Resulting preliminary mapping:
16
Ontology Matching
• Ontology matching tool: CIDER
• Input of the ontology matching tool
• Learner model with preliminary mappings
• Reference model
• Output: set of mappings (Alignment API format)
17
J. Gracia and E. Mena. Ontology matching with CIDER: Evaluation report for the OAEI 2008. In Proc. of 3rd Ontology Matching Workshop (OM’08), at ISWC’08, Karlsruhe, Germany, volume 431, pages 140-146. CEUR-WS, October 2008
Ontology Matching
18
Improvement of terminology
Learner model: Reference model:
equivalent terms with different label
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Ontology Matching
19
Missing and extra terms in the learner model
Learner model: Reference model:
missing termextra term
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Ontology Matching
20
Missing hierarchical relationships
Reference model:
missing term
equivalent terms
Learner model:
subclass of
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Semantic Reasoning
21
Inconsistency between hierarchies
Reference model:
Learner model:
equivalent terms
Disjoint classes
INCONSISTENT HIERARCHIES!
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Structure Comparison
22
Missing QR structures
Learner model: Reference model:
missing model structures
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Outline
23
1. Introduction
1. Qualitative Reasoning Modelling and Simulation
2. Application of Semantic Techniques
3. Existing approaches
2. Semantic Grounding
3. Ontology-Based Feedback
1. Types of feedback
2. Techniques of OBF
4. Some numbers
5. Conclusions
6. What’s going on...
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Experimental Evaluation
Q1. Are Semantic Web resources suitable for grounding specific domain vocabularies?
Q2. Are the state-of-the-art ontology matching tools suitable for the alignment of QR models?
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Some Research Questions
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Q1 – Semantic Web resources
Knowledge source Coverage RatioDBpedia 72%OpenCyc 69%WordNet 45%Watson 47%
25
Tested 1686 different English words coming from DynaLearn glossaries
Knowledge source Coverage Ratio
DBpedia + Yahoo Spelling Suggestion
78%
What if we fix spelling errors and suggest nearby terms?: “fiter feeding” “filter feeding”
Coverage Study
What if we combine several sources?:
Knowledge source Coverage Ratio
DBpedia + OpenCyc 87%
DBpedia + Watson 73%
Dbpedia + WordNet 72%
Dbpedia + OpenCyc + WordNet + Watson 88%
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Q1 – Semantic Web resources
• Tested 909 English labels covered by DBpedia, randomly selected from DynaLearn glossaries
• Asked 8 expert evaluators, each one evaluated between 200-300 groundings. Each grounding was double-evaluated
• Question: For each grounded term, are all the relevant meanings that you have in mind contained in the set of grounding candidates? If yes, mark the relevant ones.
• Average accuracy: 83%
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Accuracy Study
Inter-evaluator Agreement LevelPolysemy Agr eement (any) Cohen's Kappa
21,35 85% 0,47
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Q2 - Ontology Matching
• Golden standard defined by experts• Eight QR models grouped by pairs• Semantic equivalences between them were identified• Result: reference alignment file
• Separated ontology alignment: CIDER, Falcon
• Each produced alignment was compared to the golden standard
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Model Matching Experiment
Precision RecallCIDER 92% 95%Falcon 67% 95%
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
W. Hu and Y. Qu. Falcon-ao: A practical ontology matching system. Journal of Web Semantics, 6(3):237-239, 2008
Outline
1. Introduction
1. Qualitative Reasoning Modelling and Simulation
2. Application of Semantic Techniques
3. Existing approaches
2. Semantic Grounding
3. Ontology-Based Feedback
1. Types of Feedback
2. Techniques of OBF
4. Some numbers
5. Conclusions
6. What’s going on...
28Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Conclusions
• Support the creation of semantically networked models to
share and reuse conceptual knowledge
• QR models are exported into an ontological language and
grounded to an external common vocabulary
• Ontology matching techniques used to get quality feedback
29
Conclusions
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Outline
1. Introduction
1. Qualitative Reasoning Modelling and Simulation
2. Application of Semantic Techniques
3. Existing approaches
2. Semantic Grounding
3. Ontology-Based Feedback
1. Types of feedback
2. Techniques of OBF
4. Some numbers
5. Conclusions
6. What’s going on...
30Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
What’s going on…
31
Future Work
• Run usability studies on our ontology-based feedback
• Enrich our ontology matching based techniques with
advanced metrics
• Provide OBF results through the virtual characters
• Model recommendation based on the community of users
• Use our system in the academic domain to support
semantic-guided learning
• Publish this semantic data in the web of Linked Data
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
What’s going on…
32
OBF through virtual characters
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
Differences in terminology 2/8
The quantity Death rate of your model is equivalent to the quantity Mortality of the reference model. More info.
Do you want to rename the term as Mortality?
Yes No
Thanks for your attention!
33
Jorge Gracia
Facultad de Informática
Universidad Politécnica de Madrid
Campus de Montegancedo sn
28660 Boadilla del Monte, Madrid
http://www.oeg-upm.net
Phone: 34.91.3363670
Fax: 34.91.3524819
Some images under Creative Commons licence :
http://www.flickr.com/photos/binkley27/2969227096/
http://www.flickr.com/photos/tauntingpanda/14782257/
http://www.flickr.com/photos/rainforest_harley/232636845/
Semantic Techniques for Enabling Knowledge Reuse in Conceptual Modelling
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