Linked Data on the Web Query Processing Trustworthiness Olaf Hartig

What is linked data ? 2 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

The classic Web: Data exposed to the Web via HTML CIA World MovieDB Factbook 3 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

The classic Web: Information from single pages can be found via search engines 4 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

The classic Web: How about complex queries over multiple pages / data sources? What documentaries are filmed in countries with an unemployment rate above 10%? Impossible. 5 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

What do we actually want? Use the Web like a single global database CIA World MovieDB Factbook 6 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Linked data enables such a Web of data CIA World MovieDB Factbook 7 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Linked data enables such a Web of data Global Identifier: URI http://...imdb.../genres/Documentary http://cia..../Albania http://...imdb.../data/WarChildDocu CIA World MovieDB Factbook 8 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Linked data enables such a Web of data Global Identifier: URI Data Model: RDF http://...imdb.../genres/Documentary quot;War Childquot; http://cia..../Albania http://.../genre http://.../name http://.../unemp_rate http://...imdb.../data/WarChildDocu 13.2 % CIA World MovieDB Factbook 9 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Linked data enables such a Web of data Global Identifier: URI Data Model: RDF Access Mechanism: HTTP http://...imdb.../genres/Documentary quot;War Childquot; http://cia..../Albania http://.../genre http://.../name http://.../unemp_rate http://...imdb.../data/WarChildDocu 13.2 % CIA World MovieDB Factbook 10 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Linked data enables such a Web of data Global Identifier: URI Data Model: RDF Access Mechanism: HTTP http://...imdb.../genres/Documentary Connection: Typed Links quot;War Childquot; http: http://cia..../Albania http://.../genre //.../f ilmin http://.../name g_lo catio http://.../unemp_rate n http://...imdb.../data/WarChildDocu 13.2 % CIA World MovieDB Factbook 11 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Linked data enables such a Web of data Global Identifier: URI What documentaries Data Model: RDF are filmedMechanism: HTTP http://...imdb.../genres/Documentary Access in countries with an unemployment rate Links Connection: Typed above 10%? quot;War Childquot; http: http://cia..../Albania http://.../genre //.../f ilmin http://.../name g_lo catio http://.../unemp_rate n http://...imdb.../data/WarChildDocu 13.2 % CIA World MovieDB Factbook 12 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

How do we query the whole Web of linked data efficiently? 13 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Contribution (I): Efficient query processing in the Web of data 14 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

http://...imdb.../InBetweenMovie http://.../filming_location ?country . http://.../unemp_rate ?country ?u . Query http://cia..../Albania http://...imdb.../genres/Drama htt p: / /. . ./fi lm in g quot;In Betweenquot; _lo ca http://.../genre tio n http://.../name http://.../fil http://cia..../Canada ming_loca tion http://...imdb.../data/InBetweenMovie Data 15 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

http://...imdb.../InBetweenMovie http://.../filming_location ?country . http://.../unemp_rate ?country ?u . Query http://cia..../Albania http://...imdb.../genres/Drama htt p: / /. . ./fi lm in g quot;In Betweenquot; _lo ca http://.../genre tio n http://.../name http://.../fil http://cia..../Canada ming_loca tion http://...imdb.../data/InBetweenMovie Data Challenge: Intermediate results drive the discovery of further, potentially relevant data 16 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

http://...imdb.../InBetweenMovie http://.../filming_location ?country . http://.../unemp_rate ?country ?u . Query http://cia..../Albania http://...imdb.../genres/Drama htt p: http://.../unemp_rate / /. . ./fi lm in g 13.2 % quot;In Betweenquot; _lo ca http://.../genre tio n http://.../name http://.../fil http://cia..../Canada ming_loca tion http://...imdb.../data/InBetweenMovie http://.../unemp_rate 6% Data Challenge: Intermediate results drive the discovery of further, potentially relevant data 17 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Is the data trustworthy? 18 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Contribution (II): Trustworthiness in the Web of data Representing Determining Accessing 19 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

What is trustworthy Web data? Trustworthiness of RDF statements is the subjective belief or disbelief in the truth of the statements. 20 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

What is trustworthy Web data? Trustworthiness of RDF statements is the subjective belief or disbelief in the truth of the statements. uncertainty disbelief belief -1 0 1 21 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

http://...imdb.../genres/Documentary quot;War Childquot; http: http://cia..../Albania http://.../genre / / . . ./ f ilmin http://.../name g_lo catio http://.../unemp_rate n http://...imdb.../data/WarChildDocu 13.2 % 22 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

http://...imdb.../genres/Documentary quot;War Childquot; http: http://cia..../Albania http://.../genre / / . . ./ f ilmin http://.../name g_lo catio http://.../unemp_rate n http://...imdb.../data/WarChildDocu 13.2 % TrustFct 23 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

http://...imdb.../genres/Documentary quot;War Childquot; http: http://cia..../Albania http://.../genre / / . . ./ f ilmin http://.../name g_lo catio http://.../unemp_rate n http://...imdb.../data/WarChildDocu 13.2 % TrustFct( ) http://cia..../Albania http://.../unemp_rate 13.2 % 24 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

http://...imdb.../genres/Documentary quot;War Childquot; http: http://cia..../Albania http://.../genre / / . . ./ f ilmin http://.../name g_lo catio http://.../unemp_rate n http://...imdb.../data/WarChildDocu 13.2 % TrustFct( ,) http://cia..../Albania http://.../unemp_rate 13.2 % 25 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

http://...imdb.../genres/Documentary quot;War Childquot; http: http://cia..../Albania http://.../genre / / . . ./ f ilmin http://.../name g_lo catio http://.../unemp_rate n [0.8] http://...imdb.../data/WarChildDocu 13.2 % TrustFct( , ) = 0.8 http://cia..../Albania http://.../unemp_rate 13.2 % 26 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Trust assessment strategies User-based 3 Party-based rd Provenance-based 27 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Trust requirements in queries: http://...imdb.../InBetweenMovie http://.../filming_location ?country . Query Data http://cia..../China htt p: // . .. /f il m [- 0.7] i ng _lo http: http://cia..../Albania //.../fi catio lming n _loca tion [0.8] http://...imdb.../data/InBetweenMovie cation _lo ilming ./f ttp://.. h [0.68] http://cia..../Canada 28 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Trust requirements in queries: http://...imdb.../InBetweenMovie http://.../filming_location ?country . [0.5 , 1.0] Query Data http://cia..../China htt p: // . .. /f il m [- 0.7] i ng _lo http: http://cia..../Albania //.../fi catio lming n _loca tion [0.8] http://...imdb.../data/InBetweenMovie cation _lo ilming ./f ttp://.. h [0.68] http://cia..../Canada 29 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Trust requirements in queries: http://...imdb.../InBetweenMovie http://.../filming_location ?country . [0.5 , 1.0] Query Data http://cia..../China htt p: // . .. /f il m [- 0.7] i ng _lo http: http://cia..../Albania //.../fi catio lming n _loca tion [0.8] http://...imdb.../data/InBetweenMovie cation _lo ilming ./f ttp://.. h [0.68] http://cia..../Canada 30 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Thank you! 31 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)

Attribution: http://www.flickr.com/photos/mrfaber/247946146/ www.opte.org http://www.flickr.com/photos/hartkopf/1586832162/ 32 Query Processing and Trustworthiness in the Web of Linked Data (Olaf Hartig)