I-Semantics 2013 (#isem2013) presentation of Discovery Hub on-the-fly linked data exploratory search engine.

1. Discovery Hub: on-the-fly linked data exploratory search
Nicolas Marie, Fabien Gandon, Myriam Ribière
Florentin Rodio, Damien Legrand

2. CONTEXT
PROPOSITION
EVALUATION
CONCLUSION

3. Search…
ExploratoryLookup
???« members » + « The Beatles»
Precise information need Fuzzy information need
you are here

4. related work…
Aemoo Kaminskas & al. LED MORE Seevl Yovisto
Purpose Explorator
y search
Cross-domain
recommendation
Exploratory
search on
ICT domain
Film
recommendati
on
Musical
recommendati
on
Video
exploratory
search
Data DBpedia
EN +
external
services
DBpedia EN
subset
DBpedia +
external
services
DBpedia EN
subset
DBpedia EN
subset
DBpedia
EN+DE
subset
Multi-domain Yes Cross two
domains
No No, cinema No, music Yes
Query Entity
search
Entity selection in
a pre-processed
list
Entity search Entity search Entity
recognition
from Youtube.
Entity
recognition in
keywords
Algorithm EKP
filtered
view
weighted
activation
DBpedia
Ranker
sVSM algo. DBrec
algorithm
Set of
heuristics
Ranking No Yes Yes Yes Yes Yes
Explanations Wikipedia-
based
Path-based No Shared prop. Shared
properties
No
Offline proc. Yes , EKP
part
Yes Yes Yes Yes Yes
goal: domain-independent, customizable, on the fly, remote sources

5. composite interest queries
knowing my interest for X and Y what can I
discover/learn which is related to all these resources?
The Beatles Ken Loach

6. CONTEXT
PROPOSITION
EVALUATION
CONCLUSION

7. principle
results selection
ranking
sorting/categorization
explanations
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http://dbpedia.org/resource/Ken_Loach
…dbpedia.org/resource/The_Beatles

8. research questions
1. How can we discover linked resources of interest
to be explored ?
2. How to address remote LOD sources for this?
3. How to present and explain the results to the user
for an exploratory objective ?
http://fr.dbpedia.org/sparql
http://es.dbpedia.org/sparql
http://it.dbpedia.org/sparql

9. semantic adaptation of spreading activation
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10. example of semantic spreading activation

11. Album, Band, Film,
Musical Artist, Music
Genre, Person, Radio
Station, Single, Song,
Television Show
Company, Election, Film,
Journalist, Musical
Artist, Newspaper,
Office Holder,
Organisation, Politician,
School, Single,
Television Show, Writer
propagation domain propagation domain

12. research questions
1. How can we discover linked resources of interest
to be explored ?
2. How to address remote LOD sources for it?
3. How to present and explain the results to the user
for an exploratory objective ?
http://fr.dbpedia.org/sparql
http://es.dbpedia.org/sparql
http://it.dbpedia.org/sparql

13. sampling algorithm
1.sparql endpoint = http://xxx/sparql
2.seeds = xxx//The_Beatles, xxx/Ken_Loach
3. compute the propagation domain (w(i,o))
4. find a path between the seeds
5. import path nodes & their neighbors
6. for(i=1; i<=maxPulse; i++){
7. pulse();
8. if(sampleSize <= maxSampleSize){
9. extend the sample
10. }
11.}

14. iterative import
Local Kgram instance
Online LOD source

15. magic numbers
1.sparql endpoint = http://xxx/sparql
2.seeds = xxx//The_Beatles, xxx/Ken_Loach
3. compute the propagation domain (w(i,o))
4. find a path between the seeds
5. import path nodes & their neighbors
6. for(i=1; i<=maxPulse; i++){
7. pulse
8. if(sampleSize <= maxSampleSize){
9. extend the sample
10. }
11.}

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KendallTau
ResponseTime
Triples loading limit
Sample size influence on top 100 results, maxSampleSize

17. Convergence, top 100 results maxPulse
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Kendall-Tau
Sharedresults
Iterations

18. Response time histogram
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Queries response time histogram
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19. research questions
1. How can we discover linked resources of interest
to be explored ?
2. How to address remote LOD sources for it?
3. How to present and explain the results to the user
for an exploratory objective ?
http://fr.dbpedia.org/sparql
http://es.dbpedia.org/sparql
http://it.dbpedia.org/sparql

20. Discovery Hub 1.0
1. Start from what you like
or are interested in
3. Be redirected on third-party
platforms to continue the
discovery experience
Book
2.
Explore, understand, disco
ver
…

21. Discovery Hub 1.0

22. short demo

23. CONTEXT
PROPOSITION
EVALUATION
CONCLUSION

24. composite queries
• randomly combining Facebook likes of 12 users
• two queries for each participants to judge the top 20 results
- The result interests me [Strongly Disagree … Strongly Agree ]
- The result is unexpected [Strongly Disagree … Strongly Agree ]
Very interesting
Not interesting at all

25. overall
•61.6% of the results were rated as strongly relevant
or relevant by the participants.
•65% of the results were rated as strongly
unexpected or unexpected.
•35.42% of the results were rated both as strongly
relevant or relevant and strongly unexpected or
unexpected.

26. Explanatory features evaluation
Common prop. Wiki-based Graph-based OverallCommon prop. Wiki-based Graph-based Overall
Very Helpful
Not helpful at all

27. comparison SSA(Discovery Hub) vs. sVSM (More)
• Hypothesis 1: SSA gives results at least as relevant as sVSM.
• Hypothesis 2: SSA has a weaker degradation than sVSM (better end-lists).
• Hypothesis 3: results less relevant but newer to users at the end of the lists.
• Hypothesis 4: advanced search gives better results compared to standard
query.
Measure Algo Rank Mean St. Dev.
Relevance SSA 1-10 1.54 0.305
11-20 1.28 0.243
sVSM 1-10 1.42 0.294
11-20 0.93 0.228
Discovery SSA 1-10 1.10 0.247
11-20 1.21 0.228
sVSM 1-10 1.14 0.251
11-20 1.50 0.205 0
0.5
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1.5
2
2001 Erin Term Princess Fight Overall
SCORE
SSA sVSM

28. CONTEXT
PROPOSITION
EVALUATION
CONCLUSION

29. •semantic spreading activation
algorithm coupled to a graph
sampling to address remote
LOD sources.
•faceted browsing and
multiple explanations of
the results.
•on-going extensive user
evaluation
•publicly available http://discoveryhub.co
Discovery Hub : enabling exploratory
search starting from several interests
using linked data sources
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30. current work:
- propagation over multiple data sources in parallel.
- redesign of the interface: Discovery Hub 2.0 released
perspective: other applications of semantic spreading
activation

31. multi-lingual mode
dbpedia:Charles_Baudelaire sameAs fr.dbpedia:Charles_Baudelaire
French
English

32. http://discoveryhub.co/
@discovery_hub
werarediscoveryhub@gmail.com