There are growing arguments that linked data technologies can be utilised to enable user-oriented exploratory search systems for the future Internet. Recently, search over linked data has been studied in different domains and contexts. However, there is still limited insight into how conventional semantic browsers over linked data can be extended to empower exploratory search, which is open-ended, multi-faceted and iterative in nature. Empirical user studies in representative domains can identify problems and elicit requirements for innovative functionality to assist user exploration. This paper presents such an approach – a user study with a uni-focal semantic data browser over several da-tasets linked via domain ontologies is used to inform what intelligent features are needed in order to assist exploratory search through linked data. We report main problems experienced by users while conducting exploratory search tasks, based on which requirements for algorithmic support to address the observed issues are elicited. A semantic signposting approach for extending a semantic data browser is proposed as a way to address the derived requirements.

1. School of something
FACULTY OF OTHER
D Thakker et al, Assisting User Browsing over Linked Data 1
School of Computing
FACULTY OF ENGINEERING
Assisting User Browsing over Linked Data:
Requirements Elicitation with a User Study
Dhavalkumar Thakker, Vania Dimitrova, Lydia Lau,
Fan Yang-Turner, Dimoklis Despotakis

2. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 2
Semantic-enriched intelligent support to make sense of user generated content
Linked dataOntologies Content
Data
User model
Semantic Linking
Semantic tagging EnrichmentUser model update
Semantic querying
Reasoning
Nudging engineViewpoints engineDialogue planner
comparing
reflecting
connecting selectingorganising
Interface
dialogue search browse explorevisualise
Sensemaking Support Framework

3. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 3
Interactive exploration of linked semantic data
Pinta: Semantic Data Browser Shell
Ontologies Content
Data
User model
Semantic Linking
Semantic tagging EnrichmentUser model update
Semantic Querying
Reasoning
Nudging engineViewpoints engineDialogue planner
comparing
reflecting
connecting selectingorganising
Interface
dialogue search browse explorevisualise
Linked data

4. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 4
Multimedia
………Textual Description of the entity ………..
FOCUS ENTITY
Facet 1 Facts about ‘focus entity’
<‘focus entity’, predicate, object>
. .
. .
Facet 2 Terms related to ‘focus entity’
<subject, predicate, ‘focus entity’ >
. .
. .
Facet 3 Content related to ‘focus entity’
<content entry annotated with ‘focus entity’>
.
.
. .
Layout of Pinta: Uni-focal exploration

5. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 5
Examine exploratory search interaction
MusicPinta
DBPedia
Music
ontology
Data
User model
Semantic Linking
Gate & OWLIM EnrichmentUser model update
Sesame SPARQL
Reasoning
Nudging engineViewpoints engineDialogue planner
comparing
reflecting connecting selectingorganising
Interface
dialogue search browse explorevisualise
DBTune
MusicBrainz

6. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 6
Text &
Multimedia
Facts
MusicPinta: I
Focus Entity

7. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 7
Related Terms
Content with
Semantic Tags
MusicPinta: II

8. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 8
User Study with MusicPinta
Q1: How well can users without domain knowledge perform exploratory search tasks using
MusicPinta, and what is the benefit/drawback of its features?
Q2: Does browsing with MusicPinta support learning (which is traditionally associated with
exploratory search), and does semantics play a role in this?
Q3: What further improvements have to be addressed to make MusicPinta (and semantic
data browsers in general) suitable for exploratory search tasks?
12 users, voluntary participation, within subjects design
Pre-test
Profile
Schema
association
5 min
Training
Explore
tenor
saxophone
10 min
Task 1
Characteristics
of an instrument
NASA-TLX
15+5 min
Task 2
Usage of
an instrument
NASA-TLX
15+5 min
Post-test
Schema
association
Usability
10 min
Feed
back
Subjective
perception
5 min

9. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 9
Task 1: Compare & Differentiate
The music shop is extending its collection of instruments with international musical
instruments. You work in an advertising agency which has been asked to
prepare an advertisement script for some of the new instruments that will
appear in the shop. A key part of the preparation of the advertisement script is the
research of the product.
You have been asked to conduct a research of one of the new instruments, called
bouzouki, using the information available in MusicPinta. You have to identify:
•the main characteristics of bouzouki;
•up to five similar instruments to bouzouki;
•features that make bouzouki distinctive from the similar ones you have chosen.
Go to ‘Semantic Search’ in MusicPinta and type bouzouki.
Browse the content and follow links. Complete the provided form.

10. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 10
Task 1: Compare & Differentiate

11. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 11
Task 2: Select & Summarise
The music shop wants to increase the sales of its traditional musical
instruments, such as electrical guitars. It intends to do this by adding links to
creative commons album recordings with electric guitars, together with some
interesting information about these albums to inspire customers to play/buy
electric guitars or other musical instruments.
Furthermore, when displaying its electric guitar items, the shop wants to highlight
key features people look for when purchasing electric guitars.
You are asked is to conduct the research to address the above requirements by
using information provided in MusicPinta. You have to review the information about
electric guitar and identify:
•three interesting album recordings that include electric guitars and specify what is
interesting;
•key features that people look for when purchasing an electric guitar.
Go to ‘Semantic Search’ in MusicPinta and type electric guitar.
Browse the content and follow links. Complete the provided form.

12. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 12
Task 2: Select & Summarise

13. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 13
Task Performance and Difficulty
Task 1 - 70% vs Task 2 - 48%
Task 2 significantly poorer performance
significantly more frustrating
Task 2 used less ontology entities
and required mainly content exploration

14. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 14
Learning Effect
Users acquired new facts about focus and context entities
Significantly more facts related to
Task 1 than to Task 2
Positive correlation between the
number of new facts added in the
word association test and the
number of clicks on classification
level links

15. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 15
Observations
Observations about user behaviour Requirements for nudging engine

16. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 16
Conclusions
Semantics enables seamless
exploration of heterogeneous
content
Semantic facets facilitate
explorative search tasks
Semantics empowers
serendipitous learning
Semantics nudges can be
provided to improve task
success and user experiences
Measures of ‘value’ and
‘newness’ are needed
considering both ontology and
content
Context should be considered

17. D. Thakker et al. Assisting User Browsing over Linked Data: Requirements Elicitation with a User Study (ICWE 2013) 17
School of Computing
FACULTY OF ENGINEERING
Thank You
Dr. Dhavalkumar Thakker (Dhaval)
Research Fellow, University of Leeds, UK
Do you research semantic data exploration ?
Checkout & take part in Intelligent Exploration of Semantic Data(IESD) workshop series
@
http://imash.leeds.ac.uk/event/iesd.html