Context-enriched Activity Modelling

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Context-enriched Activity
Modelling
P H D W O R K ( E N D O F 1 ST Y E A R )
DIMOKLIS DESPOTAKIS
SUPERVISOR: DR. VANIA DIMITROVA
University of Leeds, School of Computing
September 2010
Outline
 Motivation & Research Problem
 Research Goal & Hypothesis
 Related Work
 Methodology
 Research Contribution
 Discussion - Questions
Motivation & Research Problem
 Research and development in simulated environments
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Platforms that are used for training (educational and professional)
High impact in current and future learning technologies
People learn through the simulated interaction experience
Does this experience reflect reality?
 Digital content published on the web
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Rich content
People search, share and exchange comments (e.g. YouTube)
Content and social web interaction intuitively mirrors the reality
How would you learn now, and in the future?
How is the digital content, enriched with knowledge, represented in
the social web spaces?
Can this combination feed simulated settings?
ImREAL : Immersive Reflective Experience-based Adaptive Learning, in Seventh Framework Programme, ICT Call
5. 2009.
Motivation & Research Problem
 Searching the web
 Why?
Exemplify your work?
 Learn other peoples’ experience
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How?
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Effectiveness?
 Precision and recall
 Awareness of knowledge
 Adaptation to individual perspectives
Motivation & Research Problem
 Application domain
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Job – related activities
Impact of learning technologies at workplace
 Experiential Learning Theory
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Learning from personal experience
Learning from other people’s experience
Reflection to everyday job practises
 Experience equals knowledge
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Knowledge of job related – activities
Knowledge is ‘‘hidden’’ in job – related contextual descriptions and
personal experience
Can we capture this knowledge?
Can digital content motivate and leverage knowledge capturing?
Kolb, A.Y. and D.A. Kolb, Experiential Learning Theory: A Dynamic, Holistic Approach to Management Learning, Education
and Development, S.J. Armstrong and C.V. Fukami, Editors. 2009, Sage: London. p. 42-68.
Research Goal & Hypothesis
 Goal
 Augment digital content related to job activities with multi –
perspective contextual information in order to:
Improve training and
 Enable context – aware intelligent search

 Hypothesis
 Semantic – enriched methods can be developed to capture
personal experiences and extract contextual descriptions of
activities embedded in digital content
 Augment digital recourses on the web with an extended
context model to increase the effectiveness of content retrieval
methods
Some Visualization
Bla bla
bla…
?
Augmented Digital Content
Digital Content presenting job-related activities
Context
Knowledge
?
Bla bla
bla…
Context
Context
Research Questions
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How to represent contextual knowledge and turn a digital resource to an
augmented and reflective digital object? This includes:
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What knowledge perspectives of an activity should be captured? This includes:
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defining the main actions in a particular job-related activity;
identifying their importance; identifying what connections may exist;
deciding how to capture and represent actions related to different individual experiences and contexts.
How to elicit contextual knowledge related to digital content with job activities?
This includes:
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changing the knowledge structure when new information is added (i.e. new contextual descriptions);
providing appropriate knowledge views (i.e. parts of the knowledge structure) according to different user
requirements.
deciding what type of digital content is most appropriate to exemplify job-related activities;
which technique can be applied to capture knowledge nuggets embedded in human descriptions and comments;
and how to derive a knowledge structure representing the extended context of the activity embedded in a digital
resource.
How to use contextual knowledge to retrieve digital content related to a specific
situation? This includes:
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discovering structural connections between different pieces of contextual knowledge and finding similarities
between context models;
defining effective algorithms for context matching.
Conceptual Framework
Related Work - Projects
 AWESOME: Sharing Dissertation Writing Experiences
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Challenge:
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support of the complex dissertation writing process in all stages;
the resolution of issues that individual characteristics of the writing process
hinder;
and the analysis and evaluation of methods to support the writing process
Work:
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AWESOME Dissertation Environment
support dynamic content creation from knowledge and experience
contributions
social scaffolding as a pedagogical solution
Semantic Media Wiki technology
Bajanki, S., et al., Use of Semantics to Build an Academic Writing Community Environment, in Proceeding of the 2009 conference on Artificial Intelligence in
Education: Building Learning Systems that Care: From Knowledge Representation to Affective Modelling. 2009, IOS Press. p. 357-364.
Related Work - Projects
 MATURE: Organizational Knowledge Maturing
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Challenge:
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evolution and eventual standardization of knowledge artefacts in parallel with the
characteristics of learning processes
reflexive knowledge base responsive to learners’ needs
career guidance
Work:
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based on is the Semantic Media Wiki
support annotation of content
knowledge construction monitoring
knowledge retrieval
user collaboration services
enrich the keyword index of an article with recommended tags
Weber, N., et al., Knowledge Maturing in the Semantic MediaWiki: A Design Study in Career Guidance, in Learning in the Synergy
of Multiple Disciplines, U. Cress, V. Dimitrova, and M. Specht, Editors. 2009, Springer Berlin / Heidelberg. p. 700-705.
Related Work - Projects
 APOSDLE: Aiding Task-based Self-directed
Learning
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Challenge:
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support the user (worker) at the very beginning of his work
adapting the system’s functionality to his learning needs
Work:
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system which recommends workplace documents
Domain Model, Task model (processes in the workplace), Competence
Performance Model (hierarchy of tasks), Knowledge Capital (repository of
annotated documents)
Ghidini, C., et al. APOSDLE: learn@work with Semantic Web Technology. in I-Know '07. 2007. Graz, Austria.
Related Work - Projects
 KP-LAB: Collective Knowledge Creation for
Workplace Learning
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Challenge
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knowledge creation and exchange for workplace learning
records of job-related activities to create pedagogical scenarios for experiential
learning
Work
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Shared Space (collaborative environment)
Semantic Wiki
Tools to support document annotation
Shared Authentic Objects
Markkanen, H., H. Barclay, and K. Schrey-Niemenmaa, Knowledge Practices Laboratory (KP-Lab) Overview. 2008.
Related Work -Project Advantages & Limitations
 Advantages
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collective knowledge elicitation has been promoted to address the need for more holistic
views of a domain;
support the learner as an individual, rather than implementing general learner models;
aid the learner in all steps of domain specific processes
 Limitations
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how is the user-learner connected with the knowledge base?
how can we aid learning in domains that activity does not involve finite states?
what solutions can be developed to bypass the limitations of existing technologies to support
domain knowledge modelling?
 Approach
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user perspectives of digital content annotation and views to be implemented within the
knowledge base structure
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provide different views of contextual descriptions, as averse to having the user as an object
based on which a system aims to adapt its functionality
new means of adaptation will be provided by enriching the knowledge augmented resources
and enable more effective content and knowledge retrieval
Augment digital records with an evolving and dynamic activity-context model
test more effective methods of knowledge capturing, which adequately overcome the
limitations that Semantic Wikis or loose knowledge elicitation schemas provide
Related Work – Capturing Knowledge

Semantic (Media) Wikis
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Advantages
 Collaborative environment
 Collective knowledge assembly: multiple users can add knowledge nuggets and annotate wiki pages to produce
links between them
 Consistency of Content: maintain changes of content
 Accessing Knowledge: accessibility of knowledge from users and search for content
 Reusing Knowledge: ontology extraction
Limitations
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Flexibility of coding and error handling
 Modularized coding will increase the maintainability and extensibility of the framework.
“On the fly” interaction with the knowledge base and the current support of ontology extraction
 mechanisms should provide the opportunity for reflection
Extend auto-completion and tag concepts recommendation with more intelligent input recommendation to increase
knowledge awareness
 Reasoning over the knowledge base to construct agents that can recommend possible input to guide the elicitation or
the retrieval.
Support for individual querying algorithms and integration with more sophisticated approaches
 Current development includes field value selection and keyword matching.
User profiling mechanisms
 A key concept in CRAM is the user. Semantic Wikis provide only basic user authentication mechanisms, while
profiling is missing
 Capturing user perspectives (extract a user model) from the content that a user has contributed is missing.
Krötzsch, M., D. Vrandečid, and M. Völkel, Semantic MediaWiki. 2006. p. 935-942.
Related Work – Capturing Knowledge
 Information Extraction
 Advantages
retrieve certain types of information from unstructured text,
usually in the form of natural language (this has been applied also
for semi-structured text, e.g. web-pages)
 entities and concepts (classes of objects and events) , and
relationships that may exist between them
 convert human generated content (text) into a machineunderstandable form
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Limitations
Unclassified concepts and relations
 Complex extraction rules have to be applied
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Related Work – Capturing Knowledge
 Information Extraction (2)
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Approach
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Ontology-based Information Extraction
 Ontologies provide a formal conceptualization of domain
 “Processes unstructured or semi-structured natural language text
through a mechanism guided by ontologies to extract certain
types of information and presents the output using ontologies.”
 Types
• Semantic annotation of text: this concerns the full guided process of
adding semantics to text concepts using an ontology: here, the text
is variable and the ontology is stable.
• Ontology population from text: here the ontology changes by adding
instances found in the text to the corresponding ontology classes.
• Ontology learning from text: this type concerns building ontology
from scratch, using text mining techniques.
Daya, W. and D. Dou, Ontology-based information extraction: An introduction and a survey of current approaches. Journal of
Information Science, 2010. 36(3): p. 306-323.
Methodology
 Application Domain Selection Criteria
a.
Content exists and/or
collected quickly
a.
Reasonable quality of content
a.
Users are available for experience
capturing
Users are available for evaluation
a.
can be
a.
Ethical issues: can we handle them
reasonably?
a.
Emotions
are
embedded
(Emotional Intelligence)
in
Existing
digital
records
presenting human experiences
(i.e. videos, images, text) or
content that can be created and
collected by the user.
Content quality refers to: digital
quality (e.g. image resolution),
richness of activity, richness of
context allocation.
Comment on digital content.
Evaluate the model and the
retrieval.
Access to activity records;
content of activity records; social
aspects (e.g. sensitivity, health,
religion).
Potential to capture the affect of
emotional states in human
experiences
Methodology
 Application Domain Selection
 Volunteering
 Research
 Job Interviews
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Great amount of digital content available freely
Wealth of contextual knowledge can be captured (students preparing for job
placements, career advisers, interviewers)
Methodology
 Platform to support the CRAM Framework
 Input:
Digital resources: videos of job interviews
 User Input: textual descriptions of the video resource (comments
and stories)
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Methodology

How to represent contextual knowledge and turn a digital resource to an augmented and
reflective digital object
The main constructive component of CRAM is
the Context Rich Activity Object (CRAO).
A CRAO is a digital object that consists of a
semantic
multi-perspective
knowledge
wrapper of a digital record to represent jobrelated activities and individual experiences.
Potential relations between CRAOs will be
explored to build a semantic graph of objects
and provide a classification framework
CRAO will be modelled as an ontology (also
CRAM).
Activity and Context will be modelled using
ontologies.
The representation of Activity will follow
Activity Theory principles.
Methodology
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What knowledge perspectives of an activity should be captured
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Defining the main actions in a particular job-related activity
 An activity is represented by a job interview video resource [Activity: A];
 Actions are represented as segments (snippets) of the video [Action: α, A= [a1, a2... an]];
 Each snippet has a start point (Ts) and an endpoint (Te) time stamp, which might be equal to present an image
captured [Ts ≤ Te];
 Each snippet is defined by the users who have commented or participated;
 Dealing with overlapped actions (time)
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Identifying context dimensions of actions
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Allen’s Interval Algebra
Retrieve content and knowledge according to input queries
description of the action presented in the video resource (CDR internal)
user’s personal experiences (CU external) related to that action
Identification and coverage of context dimensions
 Formal discussion with domain experts to derive a core structure of the activity.
 Iterations of testing and evaluation
Identifying connections that may exist
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Micro – level
 Sequence (time)
 Similar
•
•
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Connected
•
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Contextually (knowledge views)
Discovering Semantic relations using existing tools (WordNet, DISCO)
Derive patterns of annotated actions
Macro – level
 Connections between different digital content
Methodology

What knowledge perspectives of an activity should be captured (2)

Deciding how to capture and represent actions related to different individual
experiences and contexts
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Three types of Context will be implemented in CRAM:
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User Context (CU): this class refers to the contextual descriptions of personal job-related experiences and
profile records.
Digital-Record Context (CDR): this class refers to the contextual descriptions of the activity embedded
in the digital content and intuitively represents real-life human experiences in job-related settings.
Simulated Context (CS): this class refers to the contextual descriptions of (a) simulated environments
for experiential learning and (b) structures of particular contextual queries for content retrieval.
CU and CDR will be dynamic and evolving structures, while CS will be predefined.
Multi- perceptiveness is defined here as the set of different views of contextual descriptions
related to different user models (CU)
Methodology

How to elicit contextual knowledge related to digital content with job activities
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defining type of resources that will be used as records of real job-related activities
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defining the user input and the users’ role
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sample of video files has been collected of different types:
 guides
 stories
 examples
Capture and annotate actions
Provide personal experiences
Query the system
developing a prototype to test the hypothesis of capturing multi-perspective
knowledge and start collecting a corpus of resources and user input data
CRAM is the output ontology from the elicitation
mechanism.
Corpus is the set of comments for a particular video
resource that includes descriptions of the presented activity
and descriptions of personal experiences.
Guide is a set of existing ontologies that will leverage the
knowledge construction process.
Extraction Module is the Information Extraction
method, driven by the Guide
Methodology
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Continue...
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The Gate toolkit will be used for the Extraction Module to:
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Semantically annotate the Corpus based on the CRAM ontology
Populate the CRAM ontology
enrich the CRAM ontology with segments of the Guide ontologies (i.e. a second similar module
will be integrated in the Extraction Module to semantically annotate the Corpus based on the
Guide Ontologies)
Tools from GATE
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Partially ANNIE
Onto Root Gazetteer for automatic semantic annotation of text
The GATE ontology API for ontology population
Cunningham, H., et al. GATE: A framework and graphical development environment for robust NLP tools and applications.
in Proceedings of the 40th Annual Meeting of the ACL. 2002.
Methodology

How to use contextual knowledge to retrieve digital content related to a specific situation
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Provide keywords (semi-structured): having a single input field to provide keywords, an ontology reasoner can be used to
derive ontology components (classes, properties) and automatically generate SPARQL queries. Then, users can select a
matching query and retrieve the results to collect the appropriate CRAO(s) .
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Provide input fields (structured): providing existing categories and properties as input fields and recommend values will
also generate the input graph to match with the CRAM Ontology. In this way, the SPARQL query is actually defined by the
user.
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As an ultimate task for this work, the functionality of the model will be evaluated not only with individual’s context but also
with the simulated environments contextual activity aspects to align the simulated experiences with real world job-related
aspects. This task will involve the extraction of the context model (by experts in the field) and application of the above
technique to CRAM.
Methodology

Plan &Evaluation
Publication
Prototype
Experimentation
Domain
Experts Core
Model
Domain
Experts
Core User
Model
Research &
Development
Research & Development
on content and knowledge
retrieval
Data
collection
Research &
Development
Publication
Data
collection
Domain
Experts
Evaluation
Publication
Data
collection
Context
Model
Domain
Experts
Evaluation
Extensive
Evaluation
with Users
Multiperspective
Context
Model
CRAM
Research Contribution

Contribution to Context-Aware Systems: developing an advanced method for
capturing a holistic context-enriched activity model that augments digital resources and
enables intelligent context-aware retrieval.
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Contribution to User Modelling and User-adaptive Systems: capturing different
user perspectives of a job activity to derive user models and provide user-adapted content
retrieval.
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Contribution to Semantic Web: an innovative ontological approach to semantically
augment and link digital content.
It is important to state that the contribution to the above ‘technical’ areas is
driven by a key application problem – advancing technologies for learning.
Discussion - Questions
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