The document discusses Linked Data Selectors (LDS), an ontology for describing selections of fragments from web resources. It defines classes like Selector, SelectorSet, and SelectionRepresentation. Selector subclasses include Spatial, Temporal, and Declarative selectors. Examples demonstrate using LDS to describe a video snippet selection and linking slides. The goal of LDS is to enable making fine-grained connections between aggregated web resources to support learning applications.

1. Technische Universität Darmstadt
Linked Data Selectors
Kai Michael Höver & Max Mühlhäuser
Telecooperation Group

2. Telecooperation
OUTLINE
• Context and motivation
• LDS ontology design
• Usage examples
2

3. Telecooperation
Ecosystem definition
3
"ecosystem,
the
complex
of
living
organisms,
their
physical
environment,
and
all
their
interrela7onships
in
a
par7cular
unit
of
space."
[Enyclopedia
Britannica]

4. Telecooperation
(E-)Learning Ecosystem
4
"ecosystem,
the
complex
of
living
organisms,
their
(physical)
environment,
and
all
their
interrela7onships
in
a
par7cular
unit
of
space."
organisms
may
be:
-­‐
educators
-­‐
students
-­‐
friends
-­‐
family
rela7ves
-­‐
...

5. Telecooperation
(E-)Learning Ecosystem
5
"ecosystem,
the
complex
of
living
organisms,
their
(physical)
environment,
and
all
their
interrela7onships
in
a
par7cular
unit
of
space."
(physical/e-­‐)
learning
environment
contains
informa7on
resources
such
as
-­‐
slides
-­‐
lecture
recordings
-­‐
documents
-­‐
forum
discussions
-­‐
Web
documents
-­‐
...

6. Telecooperation
(E-)Learning Ecosystem
6
"ecosystem,
the
complex
of
living
organisms,
their
(physical)
environment,
and
all
their
interrela7onships
in
a
par7cular
unit
of
space."
learning
space
where
learning
and
teaching
take
place
-­‐
physical
-­‐
lecture
hall
-­‐
lab
-­‐
café
-­‐
in
the
park
-­‐
electronical/virtual
-­‐
LMS
-­‐
discussion
forums
-­‐
blogs
-­‐
OSNs
-­‐
MOOCs
-­‐
...

7. Telecooperation
(E-)Learning Ecosystem
7
"ecosystem,
the
complex
of
living
organisms,
their
(physical)
environment,
and
all
their
interrela7onships
in
a
par7cular
unit
of
space."
interrela7onships
between
-­‐
people
(social
networks)
-­‐
people
and
informa7on
resources
(author,
usage,
etc.)
-­‐
informa7on
resources
(seman7c
rela7ons)

8. Telecooperation
(E-)Learning Ecosystem
8
"ecosystem,
the
complex
of
living
organisms,
their
(physical)
environment,
and
all
their
interrela7onships
and
interac7ons
in
a
par7cular
unit
of
space."
I‘d
add
interac7ons
between
-­‐
people
(social
interac7ons)
-­‐
people
and
informa7on
resources
(how
people
interact
with
learning
resources)

9. Telecoopera7on
Web of knowledge
9
Diagram
contradicts
Diagram
illustrates
Wikipedia article
explains
Forum discussion
Q&A
Lecture Material

10. Telecooperation
The importance of anchoring annotations
•Annotation types [Agosti2007]:
•annotations as metadata: add information about the annotated information
•annotations as content: augment with additional content (add notes to an educational
resource for explaining or clarifying)
•annotations as dialogue acts: communication acts like a request or a discourse
• "Both annotations and annotated objects need to be uniquely identified" [Agosti2007]
• Anchored discussions within a specific content are more directed
and "to-the-point" [Pol2006]
• The majority of students use well-specified anchors like underlines or circles on paper
[Marshall2002]
10
Agosti, M., & Ferro, N. (2007). A formal model of annotations of digital content. ACM Trans. Inf. Syst., 26(1), 3:1-3:57
Marshall, C. C., & Brush, A. J. B. (2002). From personal to shared annotations. In CHI '02: CHI '02 extended abstracts on human factors in computing systems (pp. 812-813). ACM
Pol, J., Admiraal, W., & Simons, P. R. J. (2006). The affordance of anchored discussion for the collaborative processing of academic texts. International Journal of Computer-
Supported Collaborative Learning, 1(3), 339-357

11. Telecooperation
Missing relations in learning ecosystems
•Problem:
• Interrelationships are not (always) explicit
• even in integrated learning environments (LMS)
•many tools (CMS, forum, blogs, etc.), but separated on tool and
content level
• especially not in distributed environments
•e.g., lecture recording & discussion forum
•Why is it a problem?
•many media breaks
•missing awareness of existing learning resources
•preservation and (re-)access of parts of a learning ecosystem is
difficult
11

12. Telecooperation
Implications of the Web for learning
• The WorldWideWeb was a proposal for a Hypertext project
• Change from linear to non-linear;
from a chain of knowledge to a web of knowledge
• The early Hypertext designs of the "founding trinitiy of
hypertext" (Bush, Engelbart, Nelson) already had a focus on learning:
• Bush's Memory Extender: "A Memex is a device in which an individual store all his
books, records, and communications, and which is mechanized so that it may be
consulted with exceeding speed and flexibility. It is an enlarged supplement to his
memory" [Bush1945]
•Nelson's ELF: "Let suggest that such a system [..] could have great potential for
education
12
http://www.w3.org/Proposal.html
http://www.w3.org/History/1989/proposal.html

13. Telecooperation
Links & Learning
•"A fundamental condition for learning is the engagement with
information: making connections, setting interrelations, and
meaningful arranging of information. Doing so, information can be
better remembered if they are associated, and connections can be
created with existing knowledge." [Iske2002]
13
Iske,
S.
(2002).
Vernetztes
Wissen
:
Hypertext-­‐Strategien
im
Internet.
Wilhelm
Bertelsmann
Verlag.

14. Telecooperation
Web & Semantic Web
•The Web allows making connections
•The Semantic Web add semantic information
• Linked Data provides best practices to publish and connect data
across the Web
14
So
what's
missing
then?!
:-­‐)

15. Telecooperation
Making fine granular connections
•What we need are concepts that help us to make more fine-granular
connections between (aggregated) resources
•Using URIs not only to identify things, but also selections and
aggregations of things
15
contradicts

16. Telecooperation
Related Work
•Temporal fragments
•W3C Media Fragments (temporal parts of audio-visual materials on the Web)
•Textual selections
•XPath
•W3C POWDER (Protocol for Web Description Resources)
•Provide descriptions of (group of) online resources
•Data repositories
•SQL
•SPARQL
16
-­‐
specialized
to
specific
media
type
-­‐
XPath:
No
names
(URIs)
for
things
-­‐
don't
use
URIs
for
results
-­‐
cannot
be
dereferenced
Grouping
of
URIs
but
no
selec7ons
of
parts

17. Telecooperation
Approach: Linked Data Selectors
Ontology
•Purpose: Describing selections of dereferenceable fragments of Web
resources and their representations
•LDS Classes
•Selector
•Selector Set
•SelectionRepresentation
17

18. Telecooperation
LDS: Selector class
• A Selector
•is a fragment of exactly 1 Thing
•has representation min 0 Selection Representation
•has subselector max 1 Selector
•Selector subclasses:
•Spatial
• for spatial selections, especially at 2D layers
•Temporal
• describing selections of time or time-based media
•Declarative
• describing selections with domain specific languages (SQL, SPARQL, XPath, ...)
18

19. Telecooperation
LDS: Spatial Selector
• has Geometric Shape Description exactly 1 Thing
• A description of a geometric selection, e.g. with a 2D shape
19

20. Telecooperation
Geometrical shape excursus
20
• Formal modeling not that easy, e.g.,
• how to formally describe that a
parallelogram has two pairs of
opposite angles that have equal
measures?
Rectangle(?r), height(?r, ?h),
width(?r, ?w), equal(?h, ?w) ->
Square(?r)

21. Telecooperation
Declarative Selectors
•has Declaration
•could be a XPath description or SQL query
•Example for a history lesson:
•all US presidents that are/were members of the Democratic Part
21
select ?president where
{
?president a dbpedia-owl:President .
?president dbpprop:party <http://dbpedia.org/
resource/Democratic_Party_(United_States)> .
}

22. Telecooperation
Temporal selectors
• A selector for time-based media like audio and video
• has Temporal Description exactly 1 Thing
• Could be used in combination with time-based descriptions, like
Time Ontology for Synchronous Media or W3C OWL-Time
22

23. Telecooperation
Excursus: Time Ontology for
Synchronous Media
•TimeUnit (Defines units of time like minutes, seconds, hours. Time units can be derived from
a base unit, e.g. minutes can be derived from seconds. DerivedTimeUnits have a scaling number.)
•BaseTimeUnit
•DerivedTimeUnit
•TimeEntity
•TimeInstant
•TimeInterval
23
conversion
between
7me
units
with
SWRL:
TimeInstant(?instant),
hasScalingNumber(millisecond, ?scaling),
inSeconds(?instant, ?sec),
multiply(?result, ?sec, ?scaling)
-> inMilliSeconds(?instant, ?result)

24. Telecooperation
Selector set
•A Selector Set
• is used for grouping selectors in order to speak about more than one selector
• Usually, a set of selectors consists of 2 or more Selectors, but may be also refer to
a Resource Set for grouping resources (W3C POWDER)
• has Selector some Thing or has Selector min 2 Selector
24

25. Telecooperation
LDS: SelectionRepresentation class
25
Types
of
representa7on
A
selec7on
has
a
media
resource
that
represents
the
selec7on
result
media
resources
can
be
described
by,
e.g.,
using
the
W3C
Media
Resources
vocabulary

26. Telecooperation
Use by example
•selection of a video snippet
26
timeinterval
selectionbegin
hasStartTime
timeIntervalSelection
cutvideopresentation
hasRepresentation
TimeInterval
has individual
hasTemporalDescription
selectionend
IntervalSelector
has individual
videocut
hasMediaResource
VideoTrack
has individual
VideoRepresentation
has individual
hasEndTime
longvideo
fragmentOf
has individual
"23.0"
"http://cutvideo.mp4"
inSeconds
"83.0"
inSeconds
locator
"http://video.mp4"
locator
Interval Selection
Selection source
Selection representation

27. Telecooperation
Use by example 2: Linking slides
27
Höver, K. M., Hartle, M., & Rößling, G. (2011). A collaborative linked learning space. In ITiCSE '11: Proceedings of the 16th annual joint conference on innovation and technology in
computer science education (pp. 380-380). ACM. doi:10.1145/1999747.1999893
Höver, K. M., Hartle, M., Rößling, G., & Mühlhäuser, M. (2011). Evaluating how students would use a collaborative linked learning space. In ITiCSE '11: Proceedings of the 16th annual joint
conference on innovation and technology in computer science education (pp. 88-92). ACM. doi:10.1145/1999747.1999774
Höver, K. M., von Bachhaus, G., Hartle, M., & Mühlhäuser, M. (2012). DLH/CLLS: An open, extensible system design for prosuming lecture recordings and integrating multimedia learning
ecosystems. In IEEE international symposium on multimedia (pp. 477-482). doi:10.1109/ISM.2012.97

28. Telecooperation
Use by example 2: Linking slides
28

29. Telecooperation
Excursus: Collaborative Linked
Learning Space
29
CLLS
Lecture Recordings
described with RDF
(including log data
and augmentations)
Automatic
indexing of
slides
Automatic linking of
slides with related
resources (DBpedia,
Wikipedia, OU
Repository..)
FOAF for
users
Geolocation of users
to find near learning
partners
Integration of
learning communities
(discussion forums)
& live updatingSPARQL
A keyword

30. Telecooperation
Use by example 2: Linking slides
• link a set of slides with a paragraph of a website
30
#303slides
:hasDeclaration
SparqlSelector
has individual
:fragmentOf
Sparql Endpoint
"SELECT ?slide WHERE
{ ?slide a #Slide . ?slide
dc:subject '303 URI'.}"
#booksection
#explains
XPathSelector
has individual:hasDeclaration :fragmentOf
"http://linkeddatabook.com/
editions/1.0/""/HTML/BODY/P[59]"
Slides paragraph
#parrepresentation
:hasRepresentation
TextRepresentation
has individual
#textresource
:hasMediaResource

31. Telecooperation
Use by example 3: Linking slides with
OpenUniversity VideoPodcasts
31
#303slides
hasDeclaration
SparqlSelector
has individual
fragmentOf
Sparql Endpoint
"SELECT ?slide WHERE
{ ?slide a #Slide . ?slide
dc:subject '303 URI'.}"
#podcasts#explains
SparqlSelector
has individual
hasDeclaration
fragmentOf
Sparql Endpoint
"SELECT ?c WHERE { {?c a <http://data.open.ac.uk/
podcast/ontology/VideoPodcast>} }
FILTER regex(str(?desc), "303 uri", "i" )}}"
Slides Video Podcast

32. •Case 1: Client is able to process LDS documents
Telecooperation
Making LDS dereferenceable
32
Client Server A
http://serverA.de/LDSdocument.ttl
HTTP GET request
Accept: application/lds
HTTP OK
Process LDS
document
Present process
result

33. Telecooperation
Making LDS dereferenceable
•Case 2: Client is able to process LDS documents
33
Client Server A
http://serverA.de/LDSdocument.ttl
HTTP GET request
Accept: image/png
HTTP 303 See other
http://serverB.org/figure.png
if there is an image
representation of the
selection, redirect to
this representation
HTTP GET request
http://serverB.org/figure.png
HTTP 200 OK
Server B
http://serverB.org/figure.png

34. Telecooperation
LDS meeting LD principles
1. Use URIs as names for things
- Selections can be referenced by URIs
2. Use HTTP URIs, so that people can look up those names
- LDS URIs can be dereferenced using, e.g., 303 URIs
3. When someone looks up a URI, provide useful information, using
the standards (RDF, SPARQL)
- LDS URIs provide information about the selection type and source
4. Include links to other URIs, so that they can discover more things
- LDS documents can include links to the original source of a selection as well as
several representations of a selection
34

35. Telecooperation
Summary & future work
•We have suggested an ontology for giving selections of things individual
names (URIs)
• description of selections (include grouping and chaining)
• description of selection results
•Helping both educators and students to link things that are related
35
•Future work:
• automatic creation of representations
• integration of authentication, especially for
declarative selectors (Omnivoke Authentication
ontology)
• integration of LDS with W3C POWDER?
• user studies; visualization
• describing the dereferencing process of LDS
(content negotiation, 303 URIs)

36. Telecooperation
Thank you for listening
36
Ques8ons?
Sugges8ons
for
improvement?
:-­‐)