1. (a) Explain how RDF facilitates data integration on the Web, briefly stating
three relevant points.
[3 marks]
(b) Explain the similarities and differences between subject and object in an
RDF triple.
[3 marks]
(c) Consider the following text:
Nelson Mandela (18 July 1918 – 5 December 2013) was a South African
anti-apartheid revolutionary, political leader and philanthropist who served
as the first president of South Africa from 1994 to 1999. Mandela served 27
years in prison, split between Robben Island, Pollsmoor Prison and Victor
Verster Prison. Mandela was awarded Nobel Peace Prize. The Nelson
Mandela ornamental garden in Kingston-upon-Hull, Yorkshire, UK is
named after Mandela.
(i) Represent it as an RDF document in the Turtle syntax. You can
decide up to what level of granularity to model the text, but make sure
to use IRIs, literals, and at least a blank node or an RDF container.
Make sure to define all required prefixes. Include at least 10 triples.
You do not have to type literals.
[10 marks]
(ii) Draw the graph representation of your RDF document. Differentiate
between IRIs and literals in your drawing.
[4 marks]
– 3 –
2. (a) In the context of Ontology Engineering, explain the terms class, property,
and instance. If you plan to build an ontology of the following information,
what will be the classes, properties and instances? Name at least 3 of
each.
“Harry Potter is a series of fantasy novels written by author J. K. Rowling.
The novels chronicle the lives of a wizard, Harry Potter, and his friends
Hermione Granger and Ron Weasley, all of whom are students at
Hogwarts School of Witchcraft and Wizardry”.
[6 marks]
(b) Apart from fixing a vocabulary for representing a domain of interest,
ontologies can formalise domain knowledge in the form of axioms
(intensional knowledge). Give examples of two different kinds of axioms
and how they can be used to derive new facts. You can use any syntax
(e.g., functional or DL) for stating the axioms/facts, just make sure you use
one.
[4 marks]
(c) Write a domain or a range constraint for property R and class C in DL
syntax using number restrictions (i.e., you cannot use existential
restriction), stating exactly whether this is a domain or a range constraint.
[2 marks]
(d) Write a SPARQL query to find the most recent 10 news items found in the
following data documents:
• http://librdf.org/NEWS.rdf
• http://librdf.org/raptor/NEWS.rdf
Note: assume “http://purl.org/rss/1.0/” as a namespace for the elements type
title in the rdf documents. You may also use Dublin core namespace
(http://purl.org/dc/elements/1.1/) for the date element that you need. Each news
item has a title and a date.
[8 marks]
– 4 –
3. (a) When you publish an ontology on the Semantic Web, you do so by
publishing the OWL file (and any related documentation) under a specified
domain name, which becomes its URI.
Discuss how you would choose a suitable URI for an ontology published by
University of Kent staff, about computer games. State a possible URI for
this ontology.
[3 marks]
(b) Give three ways in which you can make your ontology more attractive for
others to discover and use.
[4 marks]
(c) What is the difference between tacit and explicit knowledge? Give an
example of each. Discuss how the status of knowledge as tacit or explicit
affects how we model it on the Semantic Web, making at least two points.
[8 marks]
(d) Interoperability refers to whether computer systems/data can operate in
conjunction with each other, exchanging and making use of mutual
information.
Define what is meant by the terms semantic interoperability and syntactic
interoperability, giving an example of each. What is the main difference
between these two types of interoperability?
[5 marks]
– 5 –
4. (a) In ten years’ time, what do you think will have happened with the Semantic
Web? Will we be adopting it more? Or less? How will it have developed?
Explain what you think regarding the use of the Semantic Web in the
future. Include in your answer at least two different justifications for the
opinions you are giving, based on content we have studied in this module.
[4 marks]
(b) The term ‘Linked Data’ refers to best practices for publishing data with
URIs and connecting these data together on the web. In this context, what
is the LOD cloud? Describe two ways in which the LOD cloud is useful.
[6 marks]
(c) Creative Commons licenses come in 6 different types: CC-BY, CC-BY-ND,
CC-BY-SA, CC-BY-NC, CC-BY-NC-ND, CC BY-NC-SA.
Imagine you wanted to use a Creative Commons license for some work
you had done. For the following scenarios, state the Creative Commons
licence you would choose to use, briefly explaining why:
[4 marks]
(i) Work which I wanted to allow people to share, reuse and build upon,
but without allowing other people to make money from that work
(ii) Work which I wanted to allow people to share and reuse but not
change
(d) Do you think the PDDL licence is better than Creative Commons licences
for licensing Semantic Web data? Give one reason to support your opinion.
[2 marks]
(e) Imagine you have an employer who has asked you to evaluate the
accuracy or quality of a dataset on the Semantic Web for them. Describe
two points you would explain to your employer, specifically on how
provenance and trust issues affect the accuracy or quality of data on the
Semantic Web
