The emergence in the last years of initiatives like the Linked Open Data (LOD) has led to a significant increase of the amount of structured semantic data on the Web. Nevertheless, the wider reuse of such public semantic data is inhibited by the difficulty for users to decide whether a given dataset is actually suitable for their needs. This is because semantic datasets typically cover diverse domains, do not follow a unified way of organizing the knowledge and may differ in a number of dimensions. With that in mind, in this paper, we report our work in progress on a goal-driven dataset summarization approach that may facilitate better understanding and reuse-oriented evaluation of available semantic data.

1. Towards Purposeful Reuse of Semantic Datasets via
Goal-Driven Data Summarization
Panos Alexopoulos, Jose Manuel Gomez Perez
6th International Conference on Advances in Semantic Processing
Porto, Portugal, October 3rd, 2013

2. Introduction
The Linked Data Use Challenge
Linking Open Data cloud diagram, by Richard Cyganiak and Anja Jentzsch. http://lod-cloud.net/
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3. Introduction
Motivating Scenario
●Assume that some entity (individual or organization) wants to reuse
public semantic datasets from the Web to:
● Enrich with them its own data.
● Use the data to provide added-value services to its users/clients.
●These organizations can be:
● Technology providers (e.g. iSOCO)
● Information providers (e.g. publishers, media, etc.)
● Knowledge-driven and knowledge-intensive organisations
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4. Data Enrichment
Why Data Reuse?
●The problem with semantic data is the high amount of time and effort
required to construct and maintain it.
●The reuse of existing public semantic data can (partially) alleviate
this problem:
● Their volume and diversity are increasing at high rates.
● Their maintenance and evolution is the responsibility of their
publishers, reducing the required efforts and costs for this task in
the organization's side
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5. Data Enrichment
Example
●A news organization wants to create and maintain a knowledge base
about European Football.
●The pace at which this knowledge changes is quite fast meaning that
the organization needs to constantly monitor these changes and
update the data.
●Much of this information is already available as public semantic data
(e.g. DBPedia).
●Thus it could be better for the organization to reuse this public data
instead of creating them from scratch.
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6. Data Enrichment
Barriers to Data Reuse
● Difficulty for knowledge engineers to decide whether a given dataset is
actually suitable for their needs.
● Semantic datasets typically cover diverse domains
● They do not follow a unified way of organizing the knowledge
● Differ in a number of features including size, coverage, granularity and
descriptiveness
● This makes difficult the following tasks:
● Assessing whether a dataset satisfies particular requirements
● Comparing different datasets to select which one is more suitable for a
given purpose.
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7. Data Reuse
Our Approach
●We suggest the provision of the ability to data consumers to derive
semantic data summaries.
●Existing summarization approaches treat the summarization task in
an application and user independent way.
●By contrast, we are interested in facilitating the generation of
requirements-oriented and goal-driven summaries that may be
significantly more helpful to users.
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8. Goal-Driven Semantic Data Summarization
Problem Description
●Key question: “Given an application scenario where semantic data is
required, how suitable is a given existing dataset for the purposes of
this scenario?”
●To answer this, users normally need to be able to:
1. Explicitly express the requirements that a dataset needs to
satisfy for a given task or goal.
2. Automatically measure/assess the extent to which a dataset
satisfies each of these requirements and compile a summary
report.
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9. Goal-Driven Semantic Data Summarization
Approach
●To implement these two capabilities we follow a checklist-based
approach.
●Checklists are practically lists of action items arranged in a
systematic manner that allow users to record the completion of each
of them.
●They are widely applied across multiple industries, like healthcare or
aviation, to ensure reliable and consistent execution of complex
operations.
●In our case we apply checklists to define and execute custom
dataset summarization tasks in the form of lists of goal-specific
requirements and associated summarization processes.
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10. Goal-Driven Semantic Data Summarization
Summarization Task Representation
●To represent custom summarization tasks according to the checklist
paradigm we have adopted the Minim model.
●This defines the following information:
● The Goals the dataset summarization task is designed to serve
● The Requirements against which the summarization task
evaluates the dataset.
● The Data Analysis Operations that the summarization task
employs in order to assess the satisfaction of its requirements
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11. Goal-Driven Semantic Data Summarization
Example Goals
●Decide if a dataset is appropriate for a Semantic Annotation scenario.
●Decide if a dataset is appropriate for a Question Answering scenario
●Determine which of two or more similar datasets best represent a
given corpus.
●Detect arising inconsistencies or other quality problems.
●…
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12. Goal-Driven Semantic Data Summarization
Example Requirements
●Evaluate the dataset’s coverage of a particular domain/topic:
Aims to measure the extent to which a dataset describes a given
domain or topic.
●Evaluate the dataset’s labeling adequacy and richness: Aims to
measure the extent to which the dataset’s elements (concepts,
instances, relations etc.) are accompanied by representative and
comprehensible labels, in one or more languages.
●Evaluate Connectivity: This requirement checks the existence of
paths between concepts or entities, i.e. whether it is possible to go
from a given concept to another on the graph and in what ways.
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13. Goal-Driven Semantic Data Summarization
Example Data Operations
●Check the existence of a particular element (concept, relation,
attribute, instance, axiom) in the dataset.
●Check the dataset’s consistency (e.g. by running a reasoner).
●Measure the number of ambiguous entities in the dataset.
●Measure the number of labeled entities.
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14. Goal-Driven Semantic Data Summarization
Application Example
●We applied our framework to assess the suitability of public datasets
for the purposes of reusing to semantically annotate texts describing
football matches from the Spanish League.
●For that, we wanted the dataset to be reused to
● Contain information about all the current teams of the Spanish
football league.
● All its entities to have at least one associated label and
● To relate teams with the players that current play in them.
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15. Goal-Driven Semantic Data Summarization
Defined Summarization Task
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16. Goal-Driven Semantic Data Summarization
Resulting Summary
● We executed this task against DBPedia and Freebase, automatically producing the
following summary report
● The system provides a yes/no answer as to whether each dataset satisfies each
requirement but also additional information on why this may or may not be the case.
● This is important because:
● A requirement might not be satisfied because of a high threshold
● A requirement might seem to be satisfied, yet that might not be actually true.
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17. Ongoing Work
Summary Generation Tool
● We are currently developing a summarization tool that enables the definition
manipulation and execution of summarization tasks as well as the
dashboard-like visualization of their output
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18. Thank you!
Questions?
Dr. Panos Alexopoulos
Semantic Applications Research
Manager
Quieres
innovar?
palexopoulos@isoco.com
(t)
+34 913 349 797
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