Semantic Web

Winter 2014/2015
Wiltrud Kessler
Monday 15:45 - 17:15
Pfaffenwaldring 5b, V 5.02
2 SWS / 3 ECTS
[LSF]

News

• [18.2.15] The exam will take place on Tuesday March 3rd at 11:00 in room V5.02. Take a look at the exams from previous years to prepare!
• [18.2.15] The practice exam will take place tomorrow (Thursday February 19th) at 11:00 in room V5.02.
• [2.2.15] Today's class is moved to room 0.009 in Pfaffenwaldring 5a.
• [27.1.15] An error in exercise 2 on sheet 3 has been fixed: It it should always be "ex:FrankNStein" instead of "ex:Manager1" and "ex:DraCula" instead of "ex:Manager2". The RDF file was correct.
• [22.1.15] The exam date has been fixed: Tuesday March 3rd, 2015.
• [1.12.14] Please register for the exams in LSF. You have until December 7th. Also tell me about it in the questionnaire in ILIAS.
• [17.11.14] Deadline for exercise sheet 2 moved to Saturday November 22nd, 23:59.
• [11.11.14] Remember to register for the exam in LSF. If you are unsure how you would like to have Semantic Web examined, take a look at the exams from previous years. My preferred way is that you register the module "Semantic Web" from the MCL 6 catalogue.
• [28.10.14] Deadline for exercise sheet 1 moved to Saturday November 1st, 23:59.
• [30.08.14] Course starts on October 13th.

Schedule and Resources

Resources (slides, examples and exercises) will be made available here. Please submit your solutions to the exercises in ILIAS.
Please bring your laptop for all sessions marked U or V+U.

Day	Topic	Resources	Chapters	More references
Block 1 "Semantic Web Basics"
13.10. (V)	The Semantic Web Vision	Slides	[HKRS08] Ch.1 [HKR09] Ch.1	The Semantic Web (2001) The Semantic Web Revisited (2006) The Semantic Web in Action (2007) Application example: Relfinder
20.10. (V)	Semantic Web Basis Technologies	Slides pets.xml	[HKRS08] Ch.2 [HKR09] App.A	Unicode Code Charts XML Validator XML Schema data types
	Linking Data with RDF	Slides pets.rdf pets.ttl	[HKRS08] Ch.3 [HKR09] Ch.2
27.10. (V+U)	Light-weight Semantics with RDFS	Slides pets2.rdf pets2.ttl	[HKRS08] Ch.4 [HKR09] Ch.3
3.11. (U)	Practice Session 1 Deadline: Saturday November 1st, 23:59	Exercise sheet 1 Template coffee: RDF/XML Turtle Template trains: RDF/XML, Turtle		RDF Validator More about Namespaces More about Properties
Block 2 "Ontologies and Logic"
10.11. (V)	Ontologies and OWL	Slides pizza_small.owl pizza.owl	[HKRS08] Ch.5 [HKR09] Ch.4	VOWL Ontology visualization
17.11. (V)	Reasoning	Slides	[HKRS08] Ch.6 [HKR09] Ch.5	Basic Description Logics
24.11. (U)	Practice Session 2 Deadline: Saturday November 22th, 23:59	Exercise sheet 2 Template countries: RDF/XML Turtle Cheat sheet		Protege Ontology Editor More about Tableaux Inference
1.12. (V+U)	Ontology Engineering Part 1	Slides	[HKR09] Ch.8
8.12. (V+U)	Ontology Engineering Part 2
15.12. (V)	Xmas Surprise: Ontology Learning	Slides		OWLExporter TextToOnto
Block 3 "The Upper Layers"
12.1. (V)	SPARQL	Slides pizza_instances.owl sparql_queries.txt	[HKRS08] Ch.7 [HKR09] Ch.7
19.1. (V)	Semantic Web Agents	Slides		Artificial Intelligence: A Modern Approach (Ch. 2, 7) Agents and the Semantic Web (2001)
	Trust	Slides		Understanding Cryptography (Ch. 6, 7, 10) The Trust Project
26.1. (V)	Semantic Web and NLP	Slides1 Slides2		CleverSearch Yummly SWSE Ask The Wiki Evi PizzaFinder Wine Agent Broccoli
2.2. (V+U)	Semantic Web Applications	Slides	[HKR09] Ch.9	RDFa recommendation CreativeCommons ontology FOAF GRDDL recommendation Geonames DBPedia LOD cloud Sindice GoPubMed
9.2. (U)	Practice Session 3 Deadline: Thursday February 4th, 23:59 (hard!!)	Exercise sheet 3 Template computers: RDF/XML Turtle Cheat sheet Trains file: RDF/XML		Twinkle
19.2. (Thu)	Practice Exam
3.3. (Tue)	Exam

The column "Chapters" refers to the chapters in the basic books (listed below) that discuss the class topic. It may be useful to read the corresponding chapter in one of the books to better understand the course content. More specific literature, links and tools for some topics can be found in the column "More references" and on my Semantic Web resources page. This is not required to pass the course, but may be interesting background reading for those interested. Additional links will be added during the course, also all the basic books contain a lot of references.

Please install Protege Ontology Editor (for OWL ontologies, block 2) and Twinkle (for SPARQL queries, block 3) on your computer and bring it to the sessions marked U or V+U.

Course Description

The Semantic Web is an initiative to make information in the web accessible to machines. In the first part of the course, basic concepts and technologies of the Semantic Web will be introduced (XML, RDF, RDFS). The second part focuses on ontologies, OWL for describing ontologies, ontology engineering, and reasoning with ontologies. In the third part, the query language SPARQL is intruduced and some applications and research topics inside the Semantic Web will be mentioned, e.g., semantic agents, semantic search or ontology learning. Apart from theoretical classes, the course will include practice sessions.

Basic text books (both cover basically parts 1 and 2 of this course):

• [HKRS08] Pascal Hitzler, Markus Krözsch, Sebastian Rudolph and York Sure. Semantic Web. Grundlagen. Springer textbook, 2008. ISBN 978-3-540-33993-9. (German, available in the library as an electronic book) [page]
• [HKR09] Pascal Hitzler, Markus Krözsch, Sebastian Rudolph. Foundations of Semantic Web Technologies. Chapman & Hall/CRC, 2009. ISBN 978-1-420-09050-5. (English, available in the library) [page]

A basic understanding of predicate logic is helpful (to the extent that is taught in the basic class of logic in the first year of Diplom and Bachelor).

Organizational Information

The course is open for students of

• M.Sc. Computational Linguistics who can get credit for it as
  • module "Semantic Web" in the electives catalogue MCL 6 (3 LP, graded) [preferred option!!]
  • part of the concentration "Statistical Natural Language Processing" or the concentration "Semantics and Syntax" (together with other classes to give a total of 12 LP).
  • one of the modules "Computational Linguistics Breadth Module [A|B|C]" in the electives catalogue MCL 7 (3 LP, non-graded)
  • one of the modules "Applications of Statistical Natural Language Processing" or "Methods in Statistical Natural Language Processing" in the electives catalogue MCL 1 together with another 2 SWS/3 LP course. (6 LP, graded)
• B.Sc. Maschinelle Sprachverarbeitung as an elective in the "Wahlbereich F: Fortgeschrittene Themen der Maschinellen Sprachverarbeitung" as part of the module "Fortgeschrittene Methoden in der Maschinellen Sprachverarbeitung" together with another 2 SWS/3 LP course.
• Other computer-science related progams as an elective.

This is a "V+PL" course. To get admitted to the exam, you will have to pass the "Vorleistung". This includes a) to get at least half the points in the mandatory exercises, b) to present at least one exercise in class and c) hand in at least part of the course project.
M.Sc. CL students who take the course as part of a concentration will have the exam as part of the oral exam for the concentration.
For all other students there will be a written exam of 60 minutes three weeks after the semester ends. The final grade for the course will be the grade you get in the exam.

Exam-related Information

The written exam will be similar to the exercises done in the practice sessions plus a few more theoretical questions. You will be provided with a "cheat sheet" in case you need to write RDF, OWL or SPARQL, so that you do not need to memorize namespace URLs or the exact spelling of owl:equivalentProperty. You can find some old exams on this page.

The oral exam for the concentration will basically include the same topics as the written exam, but with less focus on exact syntax and more about understanding.

What you should be able to do in the exam:

• Answer the question "what is the semantic web and how do we get there".
• Convert sentences in natural language to RDF/RDFS/OWL statements and write them down in Turtle and XML.
• Convert sentences in natural language to OWL statements and write them down in DL syntax.
• Explain the semantics behind all RDF/RDFS/OWL syntax elements discussed in class.
• Know the differences between RDF, RDFS and OWL.
• Explain the problem and the solution for non-binary relations in RDF/RDFS/OWL.
• List some ontology engineering issues and possible solutions.
• Understand how Tableaux works and what we want to do with it.
• Apply Tableaux to a knowledge base to see if it is satisfyable.
• Know how SPARQL works.
• Write SPARQL queries using all introduced language elements (UNION, OPTIONAL, FILTER).
• Have a general idea about what a Semantic Web agent is.
• Know what digital signatures and encryption are used for.