Personal Knowledge Graphs (PKGs) are introduced by the semantic web community as small-sized user-centric Knowledge Graphs (KGs). PKGs fill the gap of personalised representation of user data and interests on the top of big, well-established encyclopedic KGs, such as DBpedia, or domain-specific KGs, such as a medical KG. For example, the PKGs can be used in the medical domain over a medical KG to represent patient data. This presentation aims to present the rationale and the work carried out so far in the line of PKGs, and discuss potential future directions to explore the adaptation of new techniques in the educational domain in e-learning platforms. The idea is to deploy PKGs in e-learning platforms to represent users and learning activities. The development of PKGs relies on an ontology and interlinks to Linked Open Data; hence, it is adding the dimension of personalisation and explainability in users’ featured data while respecting privacy. This research design is developed for two main use cases: a collaborative search learning platform and an e-learning platform.

1. Personal Knowledge Graphs in Education
Eleni Ilkou
Supervisor: Prof. Dr. Wolfgang Nejdl
ITN Co-supervisor: Ass. Prof. Dr. Sabrina Kirrane
L3S Research Center
WU Vienna, May 2022
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 1 / 41

2. Who is Eleni?
Greece - Belgium - Germany - WU Vienna
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 2 / 41

3. Collaborators
L3S Research Center, Uni
Hannover
TIB, Uni Hannover
WBSWM Institute, Uni
Siegen
Uni Bonn
CNR Institute for
Educational Technology
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 3 / 41

4. Overview of today’s talk
Results so far & Next steps
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 4 / 41

5. The past-present
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 5 / 41

6. Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 6 / 41

7. Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 7 / 41

8. EduCOR - ISWC’21 Resource Track
The problem
ERs and OERs
low-quality metadata [1]
isolated from content-wise similar resources
lacking of high-quality services based on OERs [2]
Schemata and vocabularies
lack of online availability
lack of ability to accommodate personalised recommendations of
OERs
No model available for connecting:
different angles of education
labour market
individual needs of learners
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 8 / 41

9. EduCOR - ISWC’21 Resource Track
EduCOR
ontology
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 9 / 41

10. EduCOR - ISWC’21 Resource Track
Objectives
Can do
be used as a whole or as parts
via the patterns
fit in different educational
domains
rich metadata
compatibility with existing
educational repositories
Cannot do
provide data to specific
educational domain (expert
intervention)
automatic mapping
automatic alignment
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 10 / 41

11. EduCOR - ISWC’21 Resource Track
SOTA
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 11 / 41

12. EduCOR - ISWC’21 Resource Track
Future Steps
Automatic alignment
Quality indicators
Learning preferences
Accessibility analysis
User’s privacy
Educational KG
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 12 / 41

13. Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 13 / 41

14. Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 14 / 41

15. PKGs in e-learning - WWW’22 PhD symposium
Example
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 15 / 41

16. PKGs in e-learning - WWW’22 PhD symposium
Proposed Approach
An architecture for the creation of a PKG for a user in the back end of an
e-learning system
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 16 / 41

17. PKGs in e-learning - WWW’22 PhD symposium
1. Collaborative Search
2. e-Learning platform
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 17 / 41

18. PKGs in e-learning - WWW’22 PhD symposium
Opportunities and Challenges
Pros and Cons
+ PKGs promising new in this domain and problems
- Privacy, time dependent
- No gold-standards or baseline metrics for collaborative search and SaL
Methodology
Qualitative and quantitative
Human participants (interviews and questionnaires)
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 18 / 41

19. PKGs in e-learning - WWW’22 PhD symposium
Future Steps
Knowledge
acquisition,
maintaining, creation
and update factors of
PKGs
Privacy
Semantic
personalised
recommendations
Annotations from
tutors and direct
feedback
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 19 / 41

20. Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 20 / 41

21. PKG ontology
Ontology for PKGs in web search
Overview of the ontology
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 21 / 41

22. PKG ontology
Use case
Collaborative web search
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 22 / 41

23. Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 23 / 41

24. CollabGraph - IEEE TLT (ur)
The link between PKGs, the DBpedia KG and the creation of CollabGraph
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 24 / 41

25. CollabGraph - IEEE TLT (ur)
A graph-based collaborative search summary visualisation
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 25 / 41

26. CollabGraph - IEEE TLT (ur)
Status
Findings
Graph summary highly preferable, but not to replace classic list view -
Combo the best
Graph summary more useful in big groups and high search activity, and
closed-end learning scenarios
Next steps
Finalise implementation
On-site experiment with students
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 26 / 41

27. CollabGraph - IEEE TLT (ur)
Future Steps
Personal
graph-summary
Eye-tracking
Annotations in the
graph - commenting
Recommendations
Optimal no. of
visualised nodes
Group KG
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 27 / 41

28. The future
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 28 / 41

29. Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 29 / 41

30. Group KG
Research Paper - (WWW?)
Idea-Goal
Interlink semantic entities between KGs and PKGs
Reveal collaborative features and elements (ex. recommendations)
Evaluation-Metrics
Specific to application
ex. recommendation and relevance
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 30 / 41

31. Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 31 / 41

32. Semmantic Recommendations
Research Paper
Idea-Goal
The application to evaluate PKGs and Group KG
Achieve higher personalisation in recommendation of: topics, ERs, tests,
type of material etc
Evaluation-Metrics
Compare to baselines of recommendation algorithms by adjusting them to
educational/learning settings
Relevance, Coverage etc
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 32 / 41

33. Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 33 / 41

34. Learning Paths’ Analysis
Research Paper
Idea-Goal
Different learning paths lead to different learning outcomes
Even in case of same learning outcomes the way a subject is taught
(practical, theoretical, calculation based etc) affects students performance
Identify key parts that differentiate curricula and what makes some best
(f.e. based on PISA results)
Evaluation-Metrics
Human evaluation - Test based
High school or university setting
Over the course of a lecture or semester (maybe sth faster?)
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 34 / 41

35. Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 35 / 41

36. Smart Book
Research Paper
Idea-Goal
Idea from Semantic Pathsa
Process curricula to interlink entities
Hyperlinks between textbooks, different languages, level of material, and
areas the same content reappears
a
https://emnlp2021.semanticpaths.org/
Evaluation-Metrics
Classroom evaluation, control group vs experimental
Performance over a test and survey user experience evaluation
Additional perspective
Link with learning paths. Which curricula produces the best Data Scientist
based on a specific test?
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 36 / 41

37. Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 37 / 41

38. Edu KG
Resource Paper
Idea-Goal
Interlink educational material in a structured knowledge (ER-topics-skills)
Social impact
Evaluation-Metrics
No. of entities and relations, relevance
Research paper
Comparison to other (semi)automatic algorithms for creating KGs
QnA
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 38 / 41

39. Interested? Contact me at ilkou(at)l3s.de
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 39 / 41

40. Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 40 / 41

41. Bibliography I
Mohammadreza Tavakoli, Mirette Elias, Gábor Kismihók, and Sören
Auer.
Metadata analysis of open educational resources.
In LAK21: 11th International Learning Analytics and Knowledge
Conference, pages 626–631, 2021.
Mohammadreza Tavakoli, Mirette Elias, Gábor Kismihók, and Sören
Auer.
Quality prediction of open educational resources a metadata-based
approach.
In 2020 IEEE 20th International Conference on Advanced Learning
Technologies (ICALT), pages 29–31. IEEE, 2020.
Eleni Ilkou (L3S Research Center) Personal Knowledge Graphs in Education WU Vienna, May 2022 41 / 41