=Paper=
{{Paper
|id=Vol-1963/paper527
|storemode=property
|title=RelVis: Benchmarking OpenIE Systems
|pdfUrl=https://ceur-ws.org/Vol-1963/paper527.pdf
|volume=Vol-1963
|authors=Rudolf Schneider,Tom Oberhauser,Tobias Klatt,Felix A. Gers,Alexander Löser
|dblpUrl=https://dblp.org/rec/conf/semweb/0001OKGL17
}}
==RelVis: Benchmarking OpenIE Systems==
RelVis: Benchmarking OpenIE Systems
Rudolf Schneider, Tom Oberhauser, Tobias Klatt, Felix A. Gers, and
Alexander Löser
Beuth University of Applied Sciences, Berlin, Germany
{ruschneider, toberhauser, tklatt, gers, aloeser} @beuth-hochschule.de
Abstract. We demonstrate RelVis, a toolkit for benchmarking Open
Information Extraction(OIE) systems. RelVis enables the user to per-
form a comparative analysis among OIE systems like ClausIE, OpenIE
4.2, Stanford OpenIE or PredPatt. It features an intuitive dashboard
that enables a user to explore annotations created by OIE systems and
evaluate the impact of five common error classes. Our comprehensive
benchmark contains four data sets with overall 4522 labeled sentences
and 11243 binary or n-ary OIE relations.
1 Introduction
Open Information Extraction (OIE) is an important intermediate step for many
text mining tasks, such as summarization, relation extraction or knowledge base
construction [4][9]. OIE systems are designed for extracting n-ary tuples from di-
verse and large amounts of text as found in the web and without being restricted
to a fixed schema.
Often users desire to select a OIE system suitable for their specific application
domain. Unfortunately, there is surprisingly little work on evaluating and com-
paring results among different OIE systems. Worse, most OIE methods utilize
proprietary and unpublished data sets.
Demonstration and contribution. Ideally, one could compare different OIE
systems with a unified benchmarking suite. As a result, the user could identify
”sweet spots” of each system but also weaknesses for common error classes. The
benchmarking suite should feature a diverse set of gold annotations with several
thousands of annotated sentences. By exploring results and errors in dashboards,
the user can learn how to design the next generation of OIE systems.
We demonstrate RelVis1 , a web based open source OIE benchmarking suite,
which fulfills these requirements, see also our work in [7]. Our contributions are:
(1) We initially support four commonly used OIE systems. In addition, we permit
the users to benchmark additional OIE systems via standardized interfaces. (2)
We provide an integrated benchmark for OIE systems consisting of three news
data sets and a large OIE Benchmark from Newswire and Wikipedia. Overall,
our benchmark includes 4522 sentences and 11243 n-ary tuples. (3) Our system
permits an in-depth analysis on five different error classes, different matching
strategies and standard measures, such as f-measure, precision or recall.
1
video demonstration: https://www.youtube.com/watch?v=Hs87hIe-HEs
Fig. 1. Sentence selection view of RelVis. (1) For each sentence in the document we
show text and number of extractions by system. (2) Denotes various OIE systems with
different colors. (3) The lower right hand side visualizes error evaluation statistics.
2 Demo Walkthrough and Exploration
Startup. On system initialization, RelVis reads gold-annotations and performs a
quantitative evaluation. Next, the system stores extraction- and gold annotations
in a RDBMS.
Dashboards for exploring annotations. Now, the user can start exploring re-
sults and understanding the behaviour of each system. Figure 1 visualizes in a
web-based dashboard sentences, precision, recall and F scores for each OIE sys-
tem and for each error class. RelVis plots error distributions as a Kiviat diagram
and draws bar charts for comparing error class impacts for each OIE system. In
addition, the user can export results as tables and CSV files from the database.
Understanding and adding a single annotation. RelVis visualizes OIE extrac-
tions on sentence level. For each hit by a system, the user can drill down into a
single sentence and can understand extraction predicates, in green, or arguments,
in blue color, as shown on Figure 2.
Next, she can dive down into correct or incorrect annotations, can add la-
bels for error classes of incorrect annotations or may leave a comment, see also
Figure 2. We permit the user to apply multiple error classes to each subpart of
an annotation. Next, she can focus on a sentence of interest and can compare
extractions between different OIE systems. If no gold annotations are available
the user can create them using RelVis. Note that such a process is also feasible
with standard annotation tools, such as BRAT [10]. However in practice, we
noted that such standard tools require a lot of configuration steps to adapt to
OIE-relations. The user selects a sentence to annotate and starts with the first
annotation by clicking on the ”Add new OIE Relation” button. Next, she marks
Name Type Domain Sent. # Tuple
NYT-nary n-ary News 222 222
WEB-500 binary Web 500 461
PENN-100 binary Mixed 100 51
OIE2016 n-ary Wiki 3200 10359
Fig. 2. Specifying correctness (1), error Table 1. Data sets in RelVis
(3) and commenting on an cause (2).
the predicate and arguments in the sentence for her first annotation by selecting
them with the cursor.
Predefined common error classes. Over the years, different error classes have
been defined for evaluating OIE systems. We identified the following five types of
errors as most relevant in our previous work [7]. (1) Wrong Boundaries indicate
too large or too small boundaries for an argument or predicate of an OIE extrac-
tion. A downstream application has to filter out or correct incorrect boundaries
which may cause a drastic recall loss. (2) Redundant Extraction appear if the
OIE system does not filter out these tuples. (3) Uninformative Extraction are
tuples without any reasonable value. This error type causes additional process-
ing effort without delivering any value. (4)Missing Extraction describes relations
which were not found by a system. (5)Wrong Extraction are tuples emiting a
wrong information. It is not possible to recover from a error of this class and it
emits a wrong signal.
3 System Design
RelVis currently supports the following OIE Systems: Stanford OpenIE [1],
OpenIE 4.2 [2,5], ClausIE [3] and PredPat [11]. To add a new OIE system,
the user can either implement a Java interface or upload results in RelVis’ data
format. The system is compatible with four datasets, see Table 1, of which
two feature only binary relations with two arguments. Data sets NYT-nary and
OIE2016 also contain n-ary relations. These labeled data sets origin from [6] and
[8]. RelVis supports equal matching of boundaries in text to a gold standard. This
matching strategy delivers exact results for computing precision. However, this
strategy penalizes other, potentially correct, boundary definitions beyond the
gold standard. Dealing with multiple OIE systems and their different annotation
styles requires a less restrictive matching strategy. As second strategy we focus
on a containment match. Here an argument or predicate is considered correct
if it at least contains a gold standard annotation, hence spans from the gold
standard may be contained (fully) inside the spans of the annotation from the
OIE system. However, this strategy may label over-specific tuples as correct
and may lead to a lower precision. A containment strategy still penalizes binary
systems on n-ary data sets. Therefore we introduce as third strategy a relaxed
containment strategy which removes a penalty for wrong boundaries especially
for over specific extractions. This strategy counts an extraction correct even
when the number of arguments doesn’t match the gold standard.
4 Conclusion
To our best knowledge, RelVis is the first attempt integrating four different
OIE systems and four different data sets in a single comprehensive benchmark
system for OIE systems. It provides dashboards for in-depth qualitative eval-
uations, classifies errors in five common expendable classes and supports user
defined annotations or data sets. In our future work we will obtain output com-
patibility with BRAT annotations [10]. RelVis enables the community exploring
existing and adding home grown OIE systems and is available as open source at
https://github.com/SchmaR/RelVis.
Acknowledgement. Our work is funded by the German Federal Ministry of
Economic Affairs and Energy (BMWi) under grant agreement 01MD16011E
(Medical Allround-Care Service Solutions), grant agreement 01MD15010B (Smart
Data Web) and H2020 ICT-2016-1 grant agreement 732328 (FashionBrain).
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