1.
Use Cases
for Linked Data Visualization Model
Jakub Klímek
Jiří Helmich
Martin Nečaský
http://xrg.cz | contact@xrg.cz
XML and Web Engineering Research Group
Faculty of Mathematics and Physics
Charles University, Prague
Czech Republic
klimek@fit.cvut.cz
Faculty of Information Technology
Czech Technical University in Prague

2.
Use Cases for LDVM 2
Nowadays, a vast amount of Linked Data is available on the Internet. That’s great and that’s
exactly what we wanted.

3.
Use Cases for LDVM 3
But what happens when some LOD expert wants to get something in return from the
community and use the data present in LOD cloud?

4.
Use Cases for LDVM 4
?
??
?
He might be a bit confused, since there are many different datasets and he has no idea what
exactly they contain. Is he able to link his data with the LOD cloud? What visualizations are
available? E.g. datahub.io does not help very much.

5.
Use Cases for LDVM 5
Typically, he starts running some queries like “first 100 triples” or “first 100 concepts” against
a SPARQL endpoint. That is not very convenient.

6.
Use Cases for LDVM 6
An ideal way would be to offer him a list of visualizations that are available based on selected
dataset(s). We’ve been working on a tool for automated visualization discovery for a while.

7.
DEMO
7Use Cases for LDVM
https://www.youtube.com/watch?v=NqBGhyfNeJo

8.
Linked Data Visualization Model (LDVM)
8Use Cases for LDVM
We assemble LDVM-compliant pipelines with 4 types of components (data sources, analyzers,
transformers and visualizers).

9.
LDVM compatibility check
9
ASK {
?s s:geo ?g .
?g a s:GeoCoordinates ;
s:latitude ?lat ;
s:longitude ?lng .
}
[] ruianlink:obec <ex1>;
s:geo [
s:longitude "14.417780" ;
s:latitude "50.084552" .
] .
Output data sample
Input descriptor
Use Cases for LDVM
Each component has an input descriptor and an output data sample. If input descriptor of a
component matches to an output data sample of another, those are said to be compatible.

10.
10Use Cases for LDVM
LDVM discovery
In each iteration of the visualization discovery, we take fragments from the last iteration and try
to combine them with all available components based on compatibility checking.

11.
11Use Cases for LDVM
LDVM discovery
The iterative process terminates when no component was chained into any of the current
fragments. Pipeline is complete when it ends with a visualizer.

12.
LDVM vocabulary
12Use Cases for LDVM
 http://lov.okfn.org/dataset/lov/vocabs/ldvm
 https://github.com/payola/ldvm
We’ve published a vocabulary for describing LDVM components and pipelines. Everyone can
describe e.g. his visualizer and clearly state it’s interface by writing down its descriptors.

13.
DEMO
13Use Cases for LDVM
https://www.youtube.com/watch?v=IY3WPIq_gaM

14.
14Use Cases for LDVM
?s s:geo ?g .
?g a s:GeoCoordinates ;
s:latitude ?lat ;
s:longitude ?lng .
?s s:geo ?g ;
?p ?o .
?o a skos:Concept .
?o s:description ?d .
Descriptors are, in fact, bound to component features. Those are mandatory (like coordinates
for putting a marker on a map) or optional (like descriptions for infoboxes).

15.
LDVMi
 http://ldvm.opendata.cz
 https://github.com/payola/LDVMi
15Use Cases for LDVM

16.
LDVMi
 Read the full paper at
http://events.linkeddata.org/ldow2015/paper
s/ldow2015_paper_08.pdf
16Use Cases for LDVM

17.
Thank you for your attention
Jakub Klímek
Jiří Helmich
Martin Nečaský
http://xrg.cz | contact@xrg.cz
XML and Web Engineering Research Group
Faculty of Mathematics and Physics
Charles University, Prague
Czech Republic
klimek@fit.cvut.cz
Faculty of Information Technology
Czech Technical University in Prague