Exploratory Search Based on Linked Open Data

The Journey is the Reward

-Explorative Semantic

Search based on Linked Open Data

Sophia Antipolis, 09. October 2014

Dr. Harald SackHasso-Plattner-Institute for IT Systems Engineering

University of PotsdamDonnerstag, 9. Oktober 14

Hasso Plattner Institute for IT Systems EngineeringSemantic Technologies & Multimedia Retrieval Research Group

Donnerstag, 9. Oktober 14

• Research Topics□ Semantic Web Technologies□ Knowledge Discovery□Ontological Engineering□Multimedia Analysis & Retrieval□ Social Networking□Data/Information Visualization

• Research Projects:

Hasso Plattner Institute for IT Systems EngineeringSemantic Technologies & Multimedia Retrieval Research Group


Overview

(1) Search & Retrievaland why we are not always content with it...

(2) Semantic Analysisto better „understand“ the content

(3) Explorative Semantic Searchswitching from „retrieval“ to „discovery“

(4) Intelligent Recommendation variatio delectat - variation is delectable

The Journey is the RewardExplorative Semantic Search based onLinked Open Data


Search & Retrieval today...


Autocompletion

Google Knowledge Graph


Query by Example

Visual Analysis

RecommendationsDonnerstag, 9. Oktober 14

The Ordinary Archive is a Small World...

Jules Verne


Information Retrieval Paradigm

(Salton,G., McGill, M.J.: Introduction to Modern Information Retrieval. McGraw-Hill, New York 1983)

Set of Documents

Files of records

Set of Queries

Information requests

queryDocument

Index

based on “similarity“

IndexingQuery

Formulation

String Matching


Let‘s assume you are looking for something and you don‘t know how to phrase your search

correctly....Donnerstag, 9. Oktober 14

moon


moon spaceflight


moon spaceflight impact


moon spaceflight impact silent movie


• sometimes simple query matching with text content or metadata alone is not sufficient to fulfill the user‘s information needs

• what is missing are often the relational connections and circumstances, i.e. contextual information is needed to answer the query

• in order to achieve this the content must be „understood“

Semantic Analysis


Overview







• Authoritative• structured data• semi-structured data• natural language text

• Non-authoritative• (free) user tags and comments• restricted vocabularies

• (Media) Analysis• low level features• high level features

How to Determine the Meaning of (Meta)data?

SemanticAnalysis

reliability

context

pragmatics

location dependency

accuracy

timedependency

level ofabstraction

(Meta)data Source


From Raw (Text) Data to Semantic Entities

Neil Armstrong

Neil Armstrong, the 38-year-old civilian commander, radioes to earth an the mission control room here: „Houston, Tranquility Base here, The Eagle has landed.“

Astronaut

rdf:type

SpaceMissiondbpedia-owl:crewMember

Person

rdfs:subClassOf

stringdbpedia-owl:birth_name

datedbpedia-owl:birth_date

Event

rdfs:subClassOf

integerdbpedia-owl:crewSize

Entities

Ontologies

tag

text

image annotation


Web of Data = Linked Open Data

Neil Armstrong

Astronaut

rdf:type

Person

rdfs:subClassOf

SpaceMissiondbpedia-owl:crewMember

stringdbpedia-owl:birth_name

datedbpedia-owl:birth_date

Event

rdfs:subClassOf

integerdbpedia-owl:crewSize


Named Entity Resolution

Neil ArmstrongNeil Armstrong, the 38-year-old civilian commander, radioes to earth an the mission control room here: „Houston, Tranquility Base here, The Eagle has landed.“

text

image annotation


Text

(1) Determine possible Entity Candidates


• linguistic analysis (POS tagging)• n-gram analysis• normalization (stemming)• encoding and spelling• language dependent spellings• abbreviations & acronyms• type dependent spellings• alternative names and synonyms• fuzzy string mapping• ...



Text


• Named Entity Tagging• Persons• Locations• Organization• Time• Date• Money• ...

(2) Subsequent Filtering of Entity Candidates



(3) Disambiguation of Correct Entity

• Which entity candidate to choose depends on the context• Context Analysis

• takes into account Ambiguity, Accuracy, and Reliability of source data and mapping

TemporalContext

SpatialContext

Context Item

SocialContext

Contextual Description

ClassDiversity

Level of Structure

SourceReliability

SourceDiversity

Context Dimensions

Ambiguity Accuracy

influences influences

Relevance

determines

N.Steinmetz, H.Sack: Semantic Multimedia Information Retrieval Based on Contextual Descriptions, ESWC 2013


Neil Armstrong Tranquility Base

Houston


• Determine Candidates for all Entities within the given contextEarth

Commander

EagleMission Control


Tranquility Base

Neil Armstrong


• look for existing connections/relations among entity candidates within the given context

Mission Control



• Link Graph AnalysisNeil Armstrong, the 38-year-old civilian commander, radioes to earth an the mission control room here: „Houston, Tranquility Base here, The Eagle has landed.“



• Link Graph AnalysisNeil Armstrong, the 38-year-old civilian commander, radioes to earth an the mission control room here: „Houston, Tranquility Base here, The Eagle has landed.“

Tranquility Base

Neil Armstrong

Mission Control

Houston

Eagle

Earth


NeilArmstrong Houston Tranquility

BasemissioncontrolearthEagle Term

Entities


• Link Graph Analysis• identify connected components that cover the most term partitions• only one node per partition should be covered• strongly connected components consolidate the disambiguation



• for our example Neil Armstrong, the 38-year-old civilian commander, radioes to earth an the mission control room here: „Houston, Tranquility Base here, The Eagle has landed.“


Overview







Search vs. Exploration



V E R N E, Jules:From the Earth to the Moon, Direct in 97 Hours 20 Minutes and a Trip Round It, Sampson Low, Marston&Company, London (1873),viii, 323 p. plates.

GRC C.194.a.659, 12516.g.20


• Find another („comparable“) book, (that will interest me...)

• Find books on related topics?• How did the author / the topic develop over time? • What else would I like to read?



• Find another („comparable“) book, (that will interest me...)

• Find books on related topics?• How did the author / the topic develop over time? • What else would I like to read?


Exploratory Search


(Traditional) Libraries also enable Exploratory SearchDonnerstag, 9. Oktober 14

(Traditional) Librarians enable „intelligent“ RecommendationsDonnerstag, 9. Oktober 14

Overview







Exploratory Search based on Linked Open Data

http://dbpedia.org/resource/From_the_Earth_to_the_Moon


http://dbpedia.org/page/From_the_Earth_to_the_Moon

http://dbpedia.org/page/From_the_Earth_to_the_Moon

Exploratory Search based on Linked Open Data:From_the_Earth_to_the_Moon

:Jules_Verne

dbpedia-owl:author

:H._G._Wells

dbpedia-owl:influenced

dbpedia-owl:Bookrdf:type

category:1865_novels

category:Frence_science_fiction_novels

category:Novels_by_Jules_Verne

category:Moon_in_fiction

category:Fictional_rivalries

category:Novels_set_in_Florida

category:1860s_science_fiction_novels

...

dcterms:subject

:In_Search_of_the_Castaways

dbprop:preceded_by


Similar Results ➞ belong to consistent categories

• category:French_science_fiction_novels• category:Moon_in_fiction• category:Novels_by_Jules_Verne• category:American_Civil_War_novels• category:Novels_set_in_Florida• category:1860s_science_fiction_novels• category:1865_novels• category:Fictional_rivalries


http://dbpedia.org/resource/Category:American_Civil_War_novels


http://dbpedia.org/resource/Category:Novels_set_in_Florida


http://dbpedia.org/resource/Category:1860s_science_fiction_novels


http://dbpedia.org/resource/Category:1865_novels


http://dbpedia.org/resource/Category:Fictional_rivalries





http://dbpedia.org/resource/Category:Moon_in_fiction











Problem: too „similar“ Recommendations (in the long run)













Serendipity helps to improve the Quality of Discovery & Exploration

Serendipity:

• finding a solution to a problem that is relevant but not intentionally thought of

• a recommended item is a seredipitious discovery if it is interesting and positively surprising because one was not in search for any of its kind

Relevance Unexpectedness+=

Serendipity Donnerstag, 9. Oktober 14

Serendipity helps to improve the Quality of Discovery & Exploration

Relevance:

• In the general case, often referenced (cited) facts are considered more relevant

• In the special case, the relevance of a fact must be adapted to the current (personal) context

Unexpectedness:

• the likelyhood of co-occurrence should be low

combine • similarity based recommendations • with serendipitiuos but relevant findings

ExplorationDonnerstag, 9. Oktober 14

Serendipity: Skip most comon (similar) categories (classes)

category:1865_novels

category:Frence_science_fiction_novels

category:Novels_by_Jules_Verne

category:Moon_in_fiction

category:Fictional_rivalries

category:Novels_set_in_Florida

category:1860s_science_fiction_novels

...

most comon (similar) category for a specific entity • contains the most similar entities for this specific entity

dcterms:subject


Similarity ≈ Sharing comon Properties

dbpedia-owl:Bookrdf:typerdf:type

dbpedia:Science_Fictiondbpedia-owl:literaryGenre dbpedia-owl:literaryGenre

dbpedia-owl:author dbpedia-owl:author

dbpedia:Jules_Verne

dbpedia:Voyages_Extraordinairesdbpedia-owl:series dbpedia-owl:series

Francedbprop:country dbprop:country

category:Moon_in_fictiondcterms:subject dcterms:subject

category:French_science_fiction_novelsdcterms:subject dcterms:subject


http://dbpedia.org/resource/Voyages_Extraordinaires











http://dbpedia.org/resource/Category:French_science_fiction_novels




http://dbpedia.org/resource/Category:Novels_by_Jules_Verne












Serendipity: look for the least expected yet relevant...


Content-Based Recommendations

Industry Project: cENTERTAIN.me video recommendationhttp://mediaglobe.yovisto.com:8080/c.me-gui-0.0.1-SNAPSHOT2/


http://mediaglobe.yovisto.com:8080/c.me-gui-0.0.1-SNAPSHOT2/

http://mediaglobe.yovisto.com:8080/c.me-gui-0.0.1-SNAPSHOT2/

Overview






Dr. Harald SackHasso-Plattner-Institut für Softwaresystemtechnik, Universität PotsdamProf.-Dr.-Helmert-Str. 2-3, D-14482 Potsdam


Exploratory Search Based on Linked Open Data

Education

Transcript of Exploratory Search Based on Linked Open Data