[Elsnet-list] NLG Challenge on Content Selection (Announcement and Call for Expressions of Interest)

Nadjet Bouayad-Agha nadjet.bouayad at upf.edu
Wed Jul 4 14:36:07 CEST 2012

Announcement and Call for Expressions of Interest

European Workshop on Natural Language Generation, 2013.

We seek expressions of interest to participate in a challenge on content 
using freely available annotated semantic web data and texts. Please 
read on
and if you are interested, please contact us (see contact details at the 
end of
this call).


So far, there has been little success in Natural Language Generation
in coming up with general models of the content selection process.
Most of the researchers in the field agree that this lack of success
is because the knowledge and context (communicative goals, user
profile, discourse history, query, etc) needed for this task depend on
the application domain. This often led in the past to template- or
graph-based combined content selection and discourse structuring
approaches operating on idiosyncratically encoded small sets of input
data.  Furthermore, in many NLG-applications, target texts and
sometimes even empirical data are not available, which makes it
difficult to employ empirical approaches to knowledge elicitation.
Nonetheless, during the last decade, there has been a steady flow of new
work on content selection that employed Machine learning, heuristic
search, or a combination thereof. All of these strategies can deal with
large volumes of data.

On the other side, the continuous large-scale community-based
open-source encoding of data in Semantic Web standards such as OWL and
RDF within the Semantic Web and Linked Open Data communities means that
now more than ever we have at our disposal a large pool of semantically
encoded data and associated texts to work with.

For these reasons, we believe that the time has come to bring together
researchers working on (or interested in working on) content selection
to participate in a challenge for this task using standard freely
available web data as input.

This initial challenge presents a relatively simple content selection task
with no user model and a straightforward communicative goal so that people
are encouraged to take part and motivated to stay on for later challenges,
in which the task will be successively enhanced from gained experience.

A content determination challenge will be a chance to (i) directly
compare the performance of different types of content selection
strategies; (ii) contribute towards developing a standard
``off-the-shelf'' content selection module; and (iii) contribute
towards a standard interface between text planning and linguistic

Outline of the task:

The core of the task to be addressed can be formulated as follows:

``Build a system which, given a set of RDF triples containing facts
about a celebrity and a target text (for instance, a wikipedia-style
article about that person), selects those triples that are reflected
in the target text."

Domain and Data:

The domain will be short biographies of famous people due to the 
of Biography texts in Wikipedia and rich data representations in DBPedia or
Freebase repositories.

The data will consist, for each famous person, of a pair of RDF-triple
set and associated text(s). For each pair, the RDF data will
include both information communicated and excluded from the text. The
text may convey information not present in the RDF-triples, but this
will be kept to a minimum, always subject to using naturally-occurring
texts. All pairs should contain enough RDF-triples and text to make
the pair interesting for the content selection task.

Data Preparation and Release:

The task of data preparation consists in 1) data and texts downloading, 
pairing and
preprocessing in a suitable format, and 2) working dataset selection and 

The annotation task, in which the participants are encouraged to 
participate and
which could be supported by some automatic anchoring techniques, consists
in marking which triples are included in the text for each data-text 
triple of the
working dataset. Annotation guidelines will be provided with examples 
and descriptions
of ambiguities and other issues and how to resolve them.

The resulting annotated  working dataset will be provided to the 
participants as a
common set of ``correct answers" to exploit in their approach.

The participants will also be free to exploit a large portion of the 
non-marked paired
corpus, as well as the data semantics (i.e., ontologies and the like).


Once all participants have submitted their executable to solve the
task, the evaluation set will be processed. If timing is tight,
however, this could be done whilst the participants are still working
on the task or extra effort (for instance, from the organizers) could
be brought in. A subset of the data is randomly selected and annotated
with the selected triples by the participants.  This two-stage
approach to triple selection annotation is proposed in order to avoid
any bias on the evaluation data.

Each executable will be run against the test corpus and the selected
triples evaluated against the gold triple selection set. Since this is
formally a relatively simple task of selecting a subset of a given
set, we will use for evaluation standard precision, recall and F
measures. In addition, other appropriate metrics will be
explored---for instance, certain metrics for extractive summarisation
(which is to some extent a similar task).

The organizers will explore whether it will be feasible to select and
annotate some test examples from a different corpus and have the
systems evaluated on these as a separate task.

Proposed Timeline:

Preparation of working dataset in the summer of 2012 will start once we
gather sufficient interest from would-be participants.

The challenge proper will take place between November 2012 and May/June 
as detailed below.

Data gathering and preparation                      Jul/Aug 2012
Working dataset selection and annotation    Sept/Oct 2012
Data Release                                                      
November 2012
Evaluation dataset selection and annotation May 2013
June  2013
Publication @EWNLG                                       August 2013

Expressions of Interest:

In order to gather some quorum, we ask people interested in 
participating to
send us a mail expressing their interests as early as possible (i.e., by
the 15th of July).

The challenge is open to any approach, be it template-, rule- or 
or empirical.

We welcome approaches from other communities apart from Natural Language
Generation (NLG), i.e., summarization, semantic web, etc.

Organizing committee:

Nadjet Bouayad-Agha    TALN Group, University Pompeu Fabra, Barcelona 
Gerard Casamayor
Leo Wanner

Chris Mellish        NLG Group, University of Aberdeen, Scotland (UK).


nadjet.bouayad at upf.edu

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