semantic need: semantics from the people!

Semantic NeedSemantics from the People!

Hans-Jörg Happel, FZI Karlsruhe, Germany2010-09-18 @ SMWCon Fall 2010; Amsterdam, Netherlands

Agenda• Motivation• Extension:Semantic Need• Empirical data• Outlook & Summary

Semantic Need: Semantics from the people! - SMWCon Fall 2010; Amsterdam, Netherlands 2

MOTIVATION


Semantics for the people: Why to annotate?

• The Semantic Web provides fancy use cases, but still the creation of metadata costs effort!


Semantics from the people: What to annotate?

• Idea: Using structured queries to gauge metadata demand

• „ Semantic gap between supply and demand on the Semantic Web” [Mik09]


[Hap10]

Data (ABox)Schema (TBox)

Queries (QBox)

A

B

CD

E

F

G

Possible overlap of schema, annotations and queries

Relational databases

Desc Impl

A Data without queries and schema

Schema neededSchema mapping?

B Queried data without schema

Schema neededAdditional data sought?

C Query without schema and data

Schema neededData needed

D Queried schema without data

Data needed

E Everything fine --Additional data sought?

F Data that is never queried Schema mapping?

G Schema which is not used for annotation & querying

Schema mapping?Data needed?

6Jim Hendler@FZI • Karlsruhe, 2010-06-08

Partially unsatisfied queries („PUQs“)• Unsatisfied queries (UQs) are queries,

that cannot be satisfied from the KB (= no results)

• PUQs are a subset of UQs for which at least parts of the query can be satisfied can be related to existing classes, properties or instances


Problem patterns

• “Missing Printout Values”– Denotes the number of empty

cells in a result set for a certain structured query

– Assumption: empty cells represent an unsatisfied information need

• “Near Matches”– Denote all instances of a knowledge

base that are not part of a result set for a certain structured query due to one or more missing annotations

– Assumption: Missing/incomplete annotations of a page lead to incomplete result sets

8

Missing Printout Value

Missing Printout Value

Potential further result…

Description…… Property value isMISSING

Near Matches?

Near Matches?

Jim Hendler@FZI • Karlsruhe, 2010-06-08

EXTENSION:SEMANTIC NEED


Features• Collect needs

– Capture and store (inline) „#ask“-Queries– Offer information via SemanticQuery Manager

• Annotation guidance– Global– Special:SemanticMatches/PAGENAME– In-Page Annotation

• Side-effect features– Global query log– Automatically refresh inline queries


Screenshot: Example result table


Screenshot: Query log


Screenshot: Special:SemanticMatches/PAGE


Screenshot: In-Page Annotation


Tool status• Alpha implementation available

– …in SVN: https://waves1.fzi.de/svn/waves/trunk/SemanticNeed/ (anonymous/anonymous)

– …in Demo-Wiki: http://amazonas.fzi.de/semanticneed/– Requires small patch to core SMW (one line hook) – info at

http://www.teamweaver.org/wiki/index.php/Semantic_Need– Feedback appreciated!

• Caution!– Does currently not support some special cases (i.e.

subqueries)– Not (yet) polished (features, UI)– Contains bugs– Not tested with different MW/SMW combinations


EMPIRICAL DATA


Empirical studies• Public SMW analysis

– Crawling public SMW installations– Checking for sparse & incomplete query results

• Semantic Need Online Survey– 34 questions on SMW and Semantic Need– Target group: SMW experts (via mailinglist,

invitation) – Data collected in June/July 2010– 30 complete answers (out of 58)


Public SMW Analysis: Results• Initial results from crawling 8 public SMW

instances, using 25 (out of 285) ASK queries– Printout-Values: In average, 16% of cells in a

result set were empty due to missing annotations (up to 63% for certain queries) This allows for identifying a total of 296 missing printout values

– Near matches: In average, 22% of all potential result pages of a query lack a selective annotation (up to 94% for certain queries) This allows for identifying a total of 147 potentially missing annotations for selective properties

Jim Hendler@FZI • Karlsruhe, 2010-06-08

18

Online Survey: Experience


Online Survey: Wikis used

• n~15• Usage:

– project managment– Knowledge management– Intranet/web portal


Online Survey: Domain vs. data model


Online Survey: Dynamics• Many fixed data models• Data model changes occur at

least once per month or more in almost half of the Wikis


Online Survey: Gardening methods


Online Survey: Query result sparseness & incompleteness


Online Survey: Semantic Need


CONCLUSION AND OUTLOOK


Summary

• Open issues– What can really be considered a

need?– What else can help SMW gardeners?

• Class/Property evolution, mappings

• Next steps– Provide usable implementation– Gather feedback from field usage– Deal with special cases in SMW-QL– Define future roadmap

29Semantic Need: Semantics from the people! - SMWCon Fall 2010; Amsterdam, Netherlands

References• Extension:Semantic Need

– http://amazonas.fzi.de/semanticneed / (Demo Wiki)– http://www.mediawiki.org/wiki/Extension:Semantic_Need

• Extension:Woogle4MediaWiki (for non SMW-Wikis)– http://amazonas.fzi.de/wooglenative/ (Demo Wiki)– http://www.mediawiki.org/wiki/Extension:Woogle4MediaWiki

• Literature– [Hap09b] Hans-Jörg Happel: Towards Need-driven Knowledge Sharing in Distributed Teams. In

Proceedings of the 9th International Conference on Knowledge Management (I-KNOW 2009)– [Hap09c] Hans-Jörg Happel: Social Search and Need-driven Knowledge Sharing in Wikis with

Woogle. In Proceedings of the 5th international Symposium on Wikis and Open Collaboration (Orlando, Florida, October 25 - 27, 2009). WikiSym '09. ACM, New York, NY, 1-10.

– [Hap10] Hans-Jörg Happel: Semantic Need: Guiding Metadata Annotations by Questions People #ask. In Proceeedings of the 9th International Semantic Web Conference (ISWC 2010) (to appear)

– [Mik09]: Mika, P., Meij, E., Zaragoza, H.: Investigating the semantic gap through query log analysis. In: International Semantic Web Conference. Lecture Notes in Computer Science, vol. 5823, pp. 441–455. Springer (2009)

30Jim Hendler@FZI

• Karlsruhe, 2010-06-08

semantic need: semantics from the people!

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