<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Archiving and Interchange DTD v1.0 20120330//EN" "JATS-archivearticle1.dtd">
<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Infoboxer: Using Statistical and Semantic Knowledge to Help Create Wikipedia Infoboxes</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Roberto Yus</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Varish Mulwad</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Tim Finin</string-name>
          <email>fining@cs.umbc.edu</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Eduardo Mena</string-name>
          <email>emenag@unizar.es</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>University of Maryland</institution>
          ,
          <addr-line>Baltimore County, Baltimore</addr-line>
          ,
          <country country="US">USA</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>University of Zaragoza</institution>
          ,
          <addr-line>Zaragoza</addr-line>
          ,
          <country country="ES">Spain</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>Infoboxer uses statistical and semantic knowledge from linked data sources to ease the process of creating Wikipedia infoboxes. It creates dynamic and semantic templates by suggesting attributes common for similar articles and controlling the expected values semantically.</p>
      </abstract>
      <kwd-group>
        <kwd>Infoboxes</kwd>
        <kwd>Wikipedia</kwd>
        <kwd>DBpedia</kwd>
        <kwd>Semantic Web</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>Introduction</title>
      <p>Wikipedia is a free and collaborative encyclopedia launched in 2001 which, as
of June 2014, has more than four million English articles. Wikipedia is centered
around collaboratively creating and editing articles for a variety of topics and
subjects. The information in these articles is often split into two parts: 1)
unstructured text with details on the article's subject and 2) a semi{structured
infobox that summarizes the most important facts about the article's subject.
Thus, infoboxes are usually preferred by systems using Wikipedia content (such
as Google's Knowledge Graph or Microsoft Bing's Satori) as they are easier to
process by machines.</p>
      <p>
        Current creation of Wikipedia infoboxes is based on templates that are
created and maintained collaboratively. While templates provide a standardized
way of representing infobox information across Wikipedia articles, they pose
several challenges. Di erent communities use di erent infobox templates for the
same category articles; attribute names di er (e.g., date of birth vs. birthdate),
and attribute values are expressed using a wide variety of measurements and
units [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. Infobox templates are grouped by article categories with typically one
template associated with one category (e.g., it is hard to nd an infobox
template for article whose categories are both Artist and Politician). Given the large
number of Wikipedia categories, it is di cult to create templates for every
possible category and combination. Finally, templates are free form in nature; when
users ll attribute values no integrity check is performed on whether value is of
appropriate type for the given attribute, often leading to erroneous infoboxes.
      </p>
      <p>Infoboxer3 is a tool grounded in Semantic Web technologies that overcomes
challenges in creating and updating infoboxes, along the way making the
process easier for users. Using statistical information from Linked Open Data (LOD)
datasets, Infoboxer helps people populate infoboxes using the most popular
attributes used to describe instances for a given category or any combination of
categories, thus generating an infobox \template" automatically. For each
attribute or property Infoboxer also identi es the most popular types and provides
them as suggestions to be used to represent attribute values. The attribute value
types allows Infoboxer to enforce semantic constraints on the values entered by
the user. It also provides suggestions for attribute values whenever possible and
links them to existing entities in Wikipedia.
2</p>
      <p>
        Using DBpedia to Help Creating Wikipedia Infoboxes
The Infoboxer demonstration presented in this paper, uses DBpedia [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ], a
semistructured representation of Wikipedia's content, to implement and power all of
its features and functionalities. While our demonstration system uses DBpedia, it
could be replaced with any other LOD knowledge base, such as Yago or Freebase.
In the following sections we explain each functionality in detail.
Identifying popular attributes. The most popular attributes for a given category
are generated by computing attribute usage statistics based on instance data for
the category. Infoboxer rst obtains a list of DBpedia instances for the given
category. For example, list of instances associated with the category
dbpediaowl:SoccerPlayer include dbpedia:David Beckham and dbpedia:Tim Howard. A
list of attributes used by these instances is generated and then ordered based
on number of instances using each attribute. Duplicate counts are avoided by
noting distinct attribute for every instance only once (at this point we want to
know how many di erent instances of the category are using the property to
highlight its popularity). For example, the property dbpedia-owl:team appears
several times with the soccer player dbpedia:David Beckham (as he played for
several soccer teams), but it is only counted once.
      </p>
      <p>Sorting the list of attributes based on frequency of usage provides Infoboxer
with the most popular attributes for each category. Figure 1 shows the most
popular properties for soccer players, e.g., dbpedia-owl:team, foaf:name, and
dbpediaowl:position, along with the percentage of instances using them. This rst step
could be simpli ed by only using information about the domains and ranges of
each property (e.g., to obtain properties where the domain is a soccer player).
However, DBpedia does not impose restrictions over domain and range for most
of the properties. In fact, in a previous analysis, we detected that for DBpedia
3.9, 21% of properties have no domain de ned, 15% have no range, and 2%
have no domain and range. On July 1, Wikidata, a project focused on human
3 http://sid.cps.unizar.es/Infoboxer
edited structured Wikipedia, rolled out a similar feature which is restricted to
suggesting only popular properties4.</p>
      <p>Identifying popular range types. Infoboxer nds the most popular types used to
represent values for each attribute identi ed in the previous step. Attribute value
types is akin to rdfs:range classes associated with an attribute or a property in
an ontology. Infoboxer rst obtains a list of attribute values for a given category
and attribute by identifying list of triples in DBpedia's ABox whose subject are
instances of the given category and property, the given attribute. For example,
the category dbpedia-owl:SoccerPlayer and attribute dbpedia-owl:team generates
a list of values such as dbpedia:Arsenal F.C. and dbpedia:Korea University. A
list of value types is generated from the values and ordered based on number
of instances whose attribute values have the type. Based on the attribute, value
types are either semantic classes, such as dbpedia-owl:SoccerClub and
dbpediaowl:University, or xml datatypes such as xsd:string, xsd:integer, or xsd:datetime.
Sorting the list of types provides Infoboxer with the most popular attribute value
(or range) types.</p>
      <p>Suggesting attribute values and enforcing semantic constraints. The top three
value types for an attribute are provided as suggestions to users as they add
values for the most popular attributes in the infobox. Infoboxer also uses these
types to enforce semantic constraints on the values entered, thus ensuring infobox
correctness. In cases where value type is a semantic class, Infoboxer retrieves
instances of that class and populates them for auto-completion as user starts
lling up the value. In cases where value type is an XML datatype, Infoboxer
4 http://lists.wikimedia.org/pipermail/wikidata-l/2014-July/004148.html
shows the most popular values used as examples. Once the user enters a value,
Infoboxer checks whether value conforms to the expected type.</p>
      <p>Fixing existing infoboxes. Infoboxer also uses its functionalities to improve
existing Wikipedia infoboxes. Given an article title, Infoboxer fetches its categories
and existing attribute values. Then, it highlights popular properties with
missing values and also highlights attribute values that have an incorrect semantic
type. For example, as of June 2014, dbpedia:David Beckham has the value
dbpedia:England national football team (whose rdf:type is dbpedia-owl:SoccerClub)
for the attribute dbpedia-owl:birthPlace and Infoboxer highlights it as a possible
error as only 2% of soccer players have a soccer club as birth place (49% of them
have a dbpedia-owl:Settlement and 22% a dbpedia-owl:City). Also, Infoboxer
encourages users to update the attribute value if it is of a less popular type (e.g.,
suggesting a value of type dbpedia-owl:SoccerClub over dbpedia-owl:Organisation
for the property dbpedia-owl:team).</p>
      <p>The combination of the four functionalities allows Infoboxer to dynamically
generate infobox templates, ensure infobox correctness, and help assist in xing
existing ones. Since Infoboxer relies on KBs such as DBpedia, generated
templates will automatically evolve with change in information in KBs over time.
3</p>
    </sec>
    <sec id="sec-2">
      <title>Demonstration</title>
      <p>The demo will allow users to create new infoboxes and edit existing ones. They
begin by entering the name of a new or existing Wikipedia article and select
appropriate categories for it (e.g., Soccer Player and Scientist). Users will be
provided with the most popular attributes to be completed, along with its
popularity, based on the selected categories. For each attribute, users will also be
provided information about the top three value types; auto-complete will assist
users in selecting the appropriate value. A \Google it" button will help user re
Google search queries to discover a possible value. Also, as users start lling
values in the forms, current version of the infobox will be displayed on the side.
In summary, users will be able to experience how fast and controlled it is to
create semantically correct Wikipedia infoboxes with Infoboxer.
Acknowledgments. This research was supported by the CICYT project
TIN2010-21387-C02-02, DGA FSE, NSF awards 1228198, 1250627 and 0910838 and
a gift from Microsoft Research.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          1.
          <string-name>
            <surname>Bizer</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Lehmann</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Kobilarov</surname>
            ,
            <given-names>G.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Auer</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Becker</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Cyganiak</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Hellmann</surname>
            ,
            <given-names>S.:</given-names>
          </string-name>
          <article-title>DBpedia - a crystallization point for the web of data</article-title>
          .
          <source>Web Semantics: Science, Services and Agents on the World Wide Web</source>
          <volume>7</volume>
          (
          <issue>3</issue>
          ),
          <volume>154</volume>
          {
          <fpage>165</fpage>
          (
          <year>2009</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          2.
          <string-name>
            <surname>Morsey</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Lehmann</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Auer</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Stadler</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Hellmann</surname>
            ,
            <given-names>S.:</given-names>
          </string-name>
          <article-title>DBpedia and the Live Extraction of Structured Data from Wikipedia</article-title>
          .
          <source>Program: electronic library and information systems 46</source>
          , 157{
          <fpage>181</fpage>
          (
          <year>2012</year>
          )
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>