=Paper= {{Paper |id=Vol-1881/Overview4 |storemode=property |title=Overview of the M-WePNaD Task: Multilingual Web Person Name Disambiguation at IberEval 2017 |pdfUrl=https://ceur-ws.org/Vol-1881/Overview4.pdf |volume=Vol-1881 |authors=Soto Montalvo,Raquel Martínez,Víctor Fresno,Agustín Daniel Delgado,Arkaitz Zubiaga,Richard Berendsen |dblpUrl=https://dblp.org/rec/conf/sepln/MontalvoMFDZB17 }} ==Overview of the M-WePNaD Task: Multilingual Web Person Name Disambiguation at IberEval 2017== https://ceur-ws.org/Vol-1881/Overview4.pdf
      Overview of the M-WePNaD Task:
Multilingual Web Person Name Disambiguation
              at IberEval 2017

    Soto Montalvo1 , Raquel Martı́nez2 , Vı́ctor Fresno2 , Agustı́n D. Delgado2 ,
                     Arkaitz Zubiaga3 , Richard Berendsen4
                            1
                             URJC, soto.montalvo@urjc.es
       2
           NLP&IR Group, UNED, {raquel,vfresno,agustin.delgado}@lsi.uned.es
                  3
                    University of Warwick, a.zubiaga@warwick.ac.uk
                4
                   Luminis Amsterdam, richard.berendsen@luminis.eu



        Abstract. Multilingual Web Person Name Disambiguation is a new
        shared task proposed for the first time at the IberEval 2017 evaluation
        campaign. For a set of web search results associated with a person name,
        the task deals with the grouping of the results based on the particu-
        lar individual they refer to. Different from previous works dealing with
        monolingual search results, this task has further considered the challenge
        posed by search results written in different languages. This task allows
        to evaluate the performance of participating systems in a multilingual
        scenario. This overview summarizes a total of 18 runs received from four
        participating teams. We present the datasets utilized and the method-
        ology defined for the task and the evaluation, along with an analysis of
        the results and the submitted systems.

        Keywords: person name disambiguation on the web, document clus-
        tering, multilingualism, web search


1     Introduction
It is increasingly usual for people to turn to Internet search engines to look for
information about people. According to Google Trends, three out of the top 10
Google Searches in 2016 were linked to person names5 . However, person names
tend to be ambiguous and hence a search for a particular name likely includes
results for different individuals. In these cases, a list of individuals included
in the results along with a breakdown of different individuals would come in
handy for the user who is looking for a particular individual. This task was first
introduced in the WePS (Web People Search) campaigns6 , and attracted sub-
stantial interest in the scientific community, as manifested in a number of shared
tasks that tackled it, particularly the WePS-1, WePS-2, WePS-3 campaigns [1–
3]. These campaigns provided several annotated corpora becoming a referent for
5
    https://trends.google.com/trends/topcharts#geo&date=2016
6
    http://nlp.uned.es/weps/
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




           this problem and allowing a comparative study of the performance of different
           systems. However, all those campaigns presented a monolingual scenario where
           the query results were written in only one language.
               Despite the multilingual nature of the Web7 , existing work on person name
           disambiguation has not considered yet search results written in multiple lan-
           guages. The objective of M-WePNaD task is centered around a multilingual
           scenario where the results for a query, as well as each individual, can be written
           in different languages.
               The remainder of this paper is organized as follows. Section 2 presents the
           task. Next, Section 3 describes the datasets we released for training and testing,
           and we briefly discuss the differences between the two sets. Section 4 briefly de-
           scribes the evaluation measures. Section 5 summarizes the proposed approaches
           of the participants. Section 6 presents and discusses the results. Finally, conclu-
           sions are presented in Section 7.


           2      Task Description

           The M-WePNaD task is a person name disambiguation task on the Web focused
           on distinguishing the different individuals that are contained within the search
           results for a person name query. The person name disambiguation task can
           be defined as a clustering problem, where the input is a ranked list of n search
           results, and the output needs to provide both the number of different individuals
           identified within those results, as well as the set of pages associated with each
           of the individuals.
               The heterogeneous nature of web results increases the difficulty of this task.
           For instance, some web pages related to a certain individual could be professional
           sites (e.g. corporation web pages), while others may contain personal information
           (e.g. blogs and social profiles) and both kinds of web pages could have very little
           vocabulary in common. Particularly, [4] concluded that the inclusion of content
           from social networking platforms increases the difficulty of the task.
               While previous evaluation campaigns had been limited to monolingual sce-
           narios, the M-WePNaD task was assessed in a multilingual setting, considering
           the realistic scenario where a search engine returns results in different languages
           for a person name query. For instance, web pages with professional information
           for an individual who is not a native English speaker may be written in English,
           while other personal web pages may be written in their native language. Celebri-
           ties who are known internationally are also likely to have web pages in different
           languages.
               We compiled an evaluation corpus called MC4WePS [5], which was manually
           annotated by three experts. This corpus was used to evaluate the performance of
           multilingual disambiguation systems, enabling also evaluation for different doc-
           ument genres as the corpus includes not only web pages but also social media
           posts. The corpus was split into two parts, one for training and one for testing.
            7
                The most used language on the Web is English, followed by Chinese and Spanish.




                                                                                                                        114
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




           Participants had nearly two months to develop their systems making use of the
           training corpus. Afterwards, the test corpus was released, whereupon partici-
           pants ran their systems and sent the results back to the task organizers. The
           organizers also provided the performance scores for different baseline approaches.
           Participants were restricted to the submission of up to five different result sets.
           In this overview we present the evaluation of these submissions, which we list in
           two different rankings.



           3     Data Sets

           The MC4WePS corpus was collected in 2014, issuing numerous search queries
           and storing those that met the requirements of ambiguity and multilingualism.
               Each query includes a first name and last name, with no quotes, and searches
           were issued in both Google and Yahoo. The criteria to choose the queries took
           into account:

             – Ambiguity: non-ambiguous, ambiguous or highly ambiguous names. A per-
               son’s name is considered highly ambiguous when it has results for more than
               10 individuals. Cases with 2 to 9 individuals were considered ambiguous,
               while those with a single individual were deemed non-ambiguous.
             – Language: results can be monolingual, where all pages are written in the
               same language, or multilingual, where pages are written in more than one
               language. Additionally, for each cluster of pages belonging to the same indi-
               vidual, we considered whether the results were monolingual or multilingual.
               This was due to the fact that even though the results for a person name
               query are multilingual, the clusters for each different individual could be
               monolingual or multilingual.

               The MC4WePS dataset contains search results of 100 person names with
           a number of search results between 90 and 110 each. It is worth noting that
           different person names in the corpus have different degrees of ambiguity; in
           addition a web page can be multilingual, and not all the content in the corpus
           are regular HTML web pages, but also other kinds of documents are included,
           such as social media posts or pdf documents. A detailed description of the corpus
           can be found in [5].
               There can be overlaps between clusters as a search result could refer to two or
           more different individuals with the same name, for instance social profile pages
           with lists of different individuals with the same name. When a search result
           does not belong to any individual or the individual cannot be inferred, then this
           is annotated as “Not Related” (NR). For each query, these search results are
           grouped as a single cluster of NR results in the gold standard annotations.
               The MC4WePS corpus was randomly divided into two parts: training set
           (65%) and test set (35%).




                                                                                                                        115
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




           3.1     Training Set
           We provided participants with a single set for training, which includes 65 differ-
           ent person names, randomly sampled from the entire dataset. The list of names
           and their characteristics can be seen in Table 1. The second part of the table
           contains in the last row the average values for the different data of the whole
           training set.

                          Table 1: Characteristics of the M-WePNaD training set. #Webs
                          represents the number of search results of each person name; #Indi-
                          viduals the number of clusters related to some individual (i.e. num-
                          ber of clusters, not counting the Not Related (NR) one); %Social
                          refers the percentage of social web pages (identified by their URL-
                          domain); Top Language the most frequent language of the web
                          pages according to the annotators–ES, EN, and FR mean Span-
                          ish, English and French, respectively–; %WebsDL the percentage
                          of web pages written in different language than the most frequent
                          one; and %NRs the percentage of web pages annotated as NR.

           Person Name       #Webs #Individuals %Social Top Language %WebsDL %NRs
           adam rosales       110       8         9.09       EN        0.91   10.0
           albert claude      106       9        10.38       EN       13.21  24.53
           álex rovira       95       20        23.16       EN       43.16   6.32
           alfred nowak       109      15         3.67       EN       30.28  66.06
           almudena sierra    100      22         12.0       ES        1.0    63.0
           amber rodrı́guez   106      73        11.32       EN        9.43  10.38
           andrea alonso      105      49         9.52       ES        6.67  20.95
           antonio camacho    109      39        24.77       EN       29.36  46.79
           brian fuentes      100      12         7.0        EN        2.0    3.0
           chris andersen     100       6         5.0        EN        26.0   2.0
           cicely saunders    110       2         7.27       EN        1.82  10.91
           claudio reyna      107       5         7.48       EN        4.67   2.8
           david cutler       98       37        15.31       EN        0.0   19.39
           elena ochoa        110      15         8.18       ES        10.0   4.55
           emily dickinson    107       1         3.74       EN        0.0    0.93
           francisco bernis   100       4         4.0        EN        50.0   29.0
           franco modigliani  109       2         2.75       EN       38.53   1.83
           frederick sanger   100       2         0.0        EN        0.0    5.0
           gaspar zarrı́as    110       3         4.55       ES        2.73   0.0
           george bush        108       4         2.78       EN        25.0  13.89
           gorka larrumbide   109       3         4.59       ES        9.17  32.11
           henri michaux      98        1         3.06       EN        7.14   1.02
           james martin       100      48         5.0        EN        2.0    14.0
           javi nieves        106       3         4.72       ES        3.77   1.89
           jesse garcı́a      109      26         6.42       EN       31.19  16.51




                                                                                                                        116
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




                                                       Table 1: (continued)

           Person Name        #Webs #Individuals %Social Top Language %WebsDL %NRs
           john harrison       109      50         15.6       EN       11.01  19.27
           john orozco         100       9         11.0       EN        4.0    20.0
           john smith          101      52        10.89       EN        0.0   10.89
           joseph murray       105      47         7.62       EN        0.95   20.0
           julián lópez      109      28         4.59       ES        6.42   1.83
           julio iglesias      109       2         2.75       ES       14.68   0.92
           katia gerreiro      110       8        10.91       EN       26.36   0.0
           ken olsen           100      41         5.0        EN        0.0    6.0
           lauren tamayo       101       8        11.88       EN        3.96  10.89
           leonor garcı́a      100      53         9.0        ES        3.0    12.0
           manuel alvar        109       4         3.67       ES        0.92  34.86
           manuel campo        103       7         3.88       ES        0.0    2.91
           marı́a dueñas      100       5         6.0        ES        14.0   0.0
           mary lasker         103       3         1.94       EN        0.0   15.53
           matt biondi         106      12        10.38       EN        9.43   5.66
           michael bloomberg 110         2         6.36       EN        0.0    1.82
           michael collins     108      31         1.85       EN        0.0   13.89
           michael hammond     100      79         20.0       EN        1.0    11.0
           michael portillo    105       2         4.76       EN        7.62   0.95
           michel bernard      100       5         0.0        FR        39.0   95.0
           michelle bachelet   107       2         8.41       EN       16.82   4.67
           miguel cabrera      108       3         5.56       EN        0.93   3.7
           miriam gonzález    110      43        11.82       ES       29.09   5.45
           olegario martı́nez  100      38         12.0       ES        15.0   10.0
           oswald avery        110       2         7.27       EN        9.09   3.64
           palmira hernández 105       37         8.57       ES       20.95  60.95
           paul erhlich         99       9         4.04       EN       16.16   7.07
           paul zamecnik       102       6         1.96       EN        2.94   6.86
           pedro duque         110       5         4.55       ES        4.55  12.73
           pierre dumont        99      39         10.1       EN       41.41  15.15
           rafael matesanz     110       6         7.27       EN       44.55   2.73
           randy miller         99      52        12.12       EN        0.0   33.33
           raúl gonzález     107      32         4.67       ES       10.28   1.87
           richard rogers      100      40         13.0       EN        9.0    16.0
           richard vaughan     108       5         4.63       ES        7.41   5.56
           rita levi           104       2         1.92       ES       47.12   1.92
           robin lópez        102      10        12.75       EN        1.96  13.73
           roger becker        103      29         4.85       EN       13.59  18.45
           virginia dı́az      106      40        11.32       ES       17.92  16.04
           william miller      107      40         7.48       EN        0.0   37.38
           AVERAGE            104.69   19.95       7.66      14.88        -   12.19




                                                                                                                        117
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




           3.2     Test Set
           The test corpus consists of 35 different person names, whose characteristics can
           be seen in Table 2. The last row shows the average values for the different data
           of the whole test set.

           3.3     Comparing Training and Test Sets
           As can be seen in Table 1 and Table 2, the training and test sets have a compara-
           ble average composition with regard to the percentages of NR search results and
           social web pages. The two sets are also similar in terms of the distribution of the
           most common language for a given person name. In the test set, the percentages
           are 28.57% ES, 68.57% EN, and 2.86% FR; whereas in the training set they are
           30.76% ES, 67.69% EN, and 1.55% FR.
               The main difference between both sets lies in the degree of ambiguity of the
           person names. Based on the threshold defined by Montalvo et al. [5] that deter-
           mines search results pertaining to more than 10 individuals are very ambiguous,
           the training set contains 54% ambiguous person names and 46% very ambiguous
           names; on the other hand, the test set contains 40% ambiguous person names
           and 60% very ambiguous names. This means that the test set is less balanced
           when it comes to the ambiguity of the names than the training set; the test set
           contains more very ambiguous names.

           3.4     Format and Distribution
           The datasets are structured in directories. Each directory corresponds to a spe-
           cific search query that matches the pattern “name-lastname”, and includes the
           search results associated with that person name. Each search result is in turn
           stored in a separate directory, named after the rank of that particular result in
           the entire list of search results. A directory with a search result contains the
           following files:
             – The web page linked by the search result. Note that not all search results
               point to HTML web pages, but there are also other document formats: pdf,
               doc, etc.
             – A metadata.xml file with the following information:
                • URL of search result.
                • ISO 639-1 codes for languages the web page is written in. It contains a
                   comma-separated list of languages where several were found.
                • Download date.
                • Name of annotator.
             – A file with the plain text of the search results, which was extracted using
               Apache TiKa (https://tika.apache.org/).
              Figure 1 shows an example of the metadata file for a search result for the
           person name query Julio Iglesias.
              The access to training and test sets was restricted to registered participants.
           The blind version of the test dataset did not include the ground truth files.8
            8
                The MC4WEPS corpus is available at http://nlp.uned.es/web-nlp/resources.




                                                                                                                        118
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




           Table 2. Characteristics of the M-WePNaD test set. #Webs represents the number
           of search results of each person name; #Individuals the number of clusters related
           to some individual (i.e. number of clusters, not counting the Not Related (NR) one);
           %Social refers the percentage of social web pages (identified by their URL-domain); Top
           Language the most frequent language of the web pages according to the annotators–
           ES, EN, and FR mean Spanish, English and French, respectively–; %WebsDL the
           percentage of web pages written in different language than the most frequent one; and
           %NRs the percentage of web pages annotated as NR.


           Person Name #Webs #Individuals %Social Top Language %WebsDL %NRs
           agustin gonzalez    99    45    8.08        ES        6.06   6.06
           albert barille      99     1    2.02        EN       47.47  11.11
           albert gomez       105    50    11.43       EN       11.43  28.57
           alberto angulo     108    49    7.41        ES        7.41   6.48
           alberto granado    107     2    3.74        ES       17.76   0.93
           aldo donelli       110     4    8.18        EN        30.0  14.55
           almudena ariza     110     6    12.73       ES        10.0   4.55
           alvaro vargas      100    50    24.0        EN        34.0    8.0
           amanda navarro     102    50    7.84        EN       41.18  28.43
           david robles       100    58     8.0        ES        35.0    7.0
           didier dupont      109    34    26.61       FR       50.46  45.87
           edward heath       103     8    1.94        EN        8.74  12.62
           hendrick janssen   104    19    7.69        EN       55.77  74.04
           jacques cousteau   109     2     5.5        EN        4.59   0.92
           john williams      102    44    18.63       EN       12.75  16.67
           jorge fernandez    107    28    4.67        ES         0.0   5.61
           jose ortega        108    40    11.11       EN        7.41  19.44
           joseph lister      109    12    8.26        EN         5.5    5.5
           liliana jimenez     90    31    23.33       ES       48.89  61.11
           marina castano     100     5     5.0        ES         0.0    2.0
           mario gomez        100    18     3.0        ES        42.0    1.0
           mark davies        105    60    17.14       EN         0.0  19.05
           mary leakey        110     2    5.45        EN         0.0   3.64
           michael hastings   100    19     5.0        EN         0.0    7.0
           michelle martinez 105     49    13.33       EN       22.86   7.62
           norah jones        101     1    6.93        EN        1.98   0.99
           peter kirkpatrick  106    35    7.55        EN         6.6  25.47
           peter mitchell     110    60    30.0        EN         0.0  21.82
           rafael morales     100    47     8.0        ES        12.0   18.0
           richard branson    100     3     6.0        EN         0.0    2.0
           rick warren         99     5    9.09        EN         0.0    0.0
           ryan gosling       103     2     6.8        EN         0.0   0.97
           thomas klett        98    33    8.16        EN       29.59  42.86
           tim duncan         103     3    3.88        EN       26.21   2.91
           william osler      106     5    3.77        EN        4.72  23.58
           AVERAGE           103.63 25.14  9.72         -       16.58  15.32




                                                                                                                        119
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




           Fig. 1. Example of metadata for a web page search result for the query Julio Iglesias.


           4     Evaluation Measures

           We use three metrics for the evaluation: Reliability (R), Sensitivity (S) and
           their harmonic mean F0.5 [6]. These metrics generalize the B-Cubed metrics [7]
           when there are overlapping clusters, as it is the case with the MC4WePS corpus.
           In particular, Reliability extends B-Cubed Precision and Sensitivity extends B-
           Cubed Recall.


           5     Overview of the Submitted Approaches

           Thirteen teams signed up for the M-WePNaD task, although only four of them
           managed to participate in the task on time, submitting a total of 18 runs.
              In what follows, we analyze their approaches from two perspectives: search
           result representation (including whether or not translation resources were used),
           and the clustering algorithms.

             – The ATMC UNED team [8] presented four runs that have in common the use
               of clustering algorithms able to estimate the number of clusters with no need
               of information from training data. Three of the four runs use the ATC algo-
               rithm [9], an algorithm that works in two phases: a phase of cluster creation
               followed by a phase of cluster fusion. Run 4 uses the ATCM algorithm [10],
               which identifies those features written the same way in several languages
               (called comparable features) and gives them a special role when comparing
               search results written in different languages without the need of translation
               resources. The author explores four different representation approaches: the
               textual features of the document with no translation (Run 1), a translated
               version of the document (Run 2), a halfway approach that uses the original
               document’s textual features in the phase of cluster creation and uses a trans-
               lation tool to translate the centroid features in the fusion cluster phase (Run
               3), and an approach that combines the original document’s textual features
               in addition to a representation based on using only the comparable features
               of web pages written in different language. On the other hand, none of the
               four approaches identifies and groups the not related search results, so all of




                                                                                                                        120
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




               them get worse results when considering all the web pages. Regarding the
               treatment of overlapping clusters, none of the four approaches deals with
               them, so a web page can only be in one cluster. Finally, the author applies
               an heuristic described in [11] to treat in a special way the web pages from
               social media platforms and people search engines.
             – The LSI UNED team’s approach [12] is mainly based on the application of
               word embeddings to represent the documents retrieved by the search engine
               as vectors. Then, these vectors are used in a clustering algorithm (developed
               by the authors and adapted to the characteristics of the corpus), where a
               similarity threshold γ determines when the grouping is carried out. To ob-
               tain the word embeddings, first they performed a removal of stopwords and
               extracted the named entities, using pre-trained word embeddings for repre-
               sentation. The tools they used were the Stanford Named Entity Recognizer9
               and ConVec10 , a publicly available collection of word vectors generated from
               Wikipedia concepts. To obtain the document representation, the authors
               calculated the average vector of all the vectors corresponding to the words
               within the document. They calculated the similarity between each document
               and the rest of the documents related to the same person name by means
               of cosine similarity. The similarity weight associated to each document was
               the average of the similarity between that document, and the rest of doc-
               uments related to the same person name. Finally, the authors considered
               that all the documents with a similarity weight above a specific γ threshold
               should be gathered in the same initial cluster. This team initially submitted
               four runs corresponding to different values of γ (γ1 = 0 : 70, γ2 = 0 : 75,
               γ3 = 0 : 80, and γ4 = 0 : 85). Finally, a fifth run was also evaluated using
               a different configuration of the system, in which all the words within the
               documents (except stop words) were considered in order to represent them,
               and not only named entities, as in the previous runs. None of their submitted
               runs deals with the multilingual nature of the task nor the overlap between
               clusters.
             – The Loz Team [13] submitted five runs that experimented with different
               settings a hierarchical agglomerative clustering (HAC) algorithm using the
               Euclidean distance as a similarity measure. They tested three different ways
               of representing the content: (1) a binary representation capturing presence
               or not of each word, (2) a weighted representation capturing the number of
               occurrences of each word, and (3) a TF-IDF metric. They also tested two
               different stoppage criteria, namely k = 5 and k = 15. With these different
               settings, the authors tested the following five combinations: (1) weighted
               representation + k = 5, (2) binary representation + k = 15, (3) TF-IDF +
               k = 15, (4) binary representation + k = 5, and (5) TF-IDF + k = 5. As
               in the previous team, none of the five runs developed by this team tackled
               the challenges posed by the multilingual nature of the dataset or the overlap
               between clusters.
            9
                https://nlp.stanford.edu/software/CRF-NER.shtml
           10
                https://github.com/ehsansherkat/ConVec




                                                                                                                        121
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




             – The PanMorCresp Team [14] submitted four runs based on the HAC algo-
               rithm. For all runs, the files with the plain text version of the search result
               are used. For each query, vector representations of the text are generated
               independently. The text is split into tokens on blank characters. The tokens
               are lowercased. Some runs use additional token normalization. Next, words
               that occur only once in the collection are removed. After creating the vocabu-
               lary, binary document vectors are created, indicating the presence or absence
               of words in a document. The cosine similarity is used to compute similari-
               ties between document vectors. None of the runs use any translation or other
               language-specific decisions. None of the runs try to detect non-related search
               results. The four runs then investigate the effect of other typical choices one
               has to make when employing HAC. First, token normalization. Run 3 and
               Run 4 eliminate punctuation. Second, which words to use in the vocabulary;
               besides effectiveness, computational efficiency plays a role here. Run 1 and
               Run 2 include the 4,000 most frequent terms. Run 3 and Run 4 remove stop
               words and include the 7,500 most frequent remaining terms. Third, how to
               compute cluster similarities. Run 1 uses complete linkage, Run 2 uses the
               average similarity between documents in both clusters, and Run 3 and Run 4
               use single linkage. Fourth, how to define the stopping criterion. Run 1 makes
               the stopping criterion depend on the query. It computes the average similar-
               ity between documents and divides this by a factor n. On the training set,
               this parameter was tuned to n = 2. Run 2, Run 3, and Run 4 use a global
               stopping criterion. Run 2 and Run 3 tune a minimal similarity threshold on
               the training corpus. For Run 3 the resulting threshold was 0.65; for Run 2 it
               is not given. Run 4 uses an exact number of clusters as a stopping criterion.


           6     Results and Discussion
           We produced two different rankings of the participants after evaluating all the
           submissions:
             – Evaluation results by not considering the Not Related results. This means
               that all the results of this kind and the corresponding cluster were not taken
               into account.
             – Evaluation results considering all web results. This means that all the results
               and the clusters were taken into account.
               Table 3 shows the results without considering Not Related results in the
           evaluation, whereas Table 4 shows the results considering all the pages. Both
           tables contain two baselines ONE IN ONE and ALL IN ONE. ONE IN ONE
           returns each search result as a singleton cluster, while ALL IN ONE returns
           only one cluster that includes all the search results. Note that these baselines
           are independent of the document representation.
               The results obtained by the ATMC UNED team runs overcome the results
           obtained by the baselines and the rest of the participants, showing the potential
           of the ATC and ATMC algorithms over the rest, particularly HAC algorithms.




                                                                                                                        122
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




                       Table 3. Evaluation results not considering Not Related results.


                           System and run number                     R        S        F0.5
                           ATMC UNED - run 3                         0.80     0.84     0.81
                           ATMC UNED - run 4                         0.79     0.85     0.81
                           ATMC UNED - run 2                         0.82     0.79     0.80
                           ATMC UNED - run 1                         0.79     0.83     0.79
                           LSI UNED - run 3                          0.59     0.85     0.61
                           LSI UNED - run 4                          0.74     0.71     0.61
                           LSI UNED - run 2                          0.52     0.93     0.58
                           LSI UNED - run 5                          0.52     0.92     0.5
                           PanMonCresp Team - run 4                  0.53     0.87     0.57
                           LSI UNED - run 1                          0.49     0.97     0.56
                           Baseline - ALL-IN-ONE                     0.47     0.99     0.54
                           Loz Team - run 3                          0.57     0.71     0.52
                           Loz Team - run 5                          0.51     0.83     0.52
                           Loz Team - run 2                          0.55     0.65     0.50
                           Loz Team - run 4                          0.50     0.81     0.50
                           PanMorCresp Team - run 3                  0.53     0.82     0.47
                           Loz Team - run 1                          0.50     0.76     0.46
                           PanMorCresp Team - run 1                  0.80     0.51     0.43
                           Baseline - ONE-IN-ONE                     1.0      0.32     0.42
                           PanMorCresp Team - run 2                  0.50     0.65     0.41




           The results obtained by all their runs are quite similar. However, Run 1 uses
           features from the original content of the web pages and gets worse results with
           respect to Run 2 and Run 3, which use a machine translation tool. Run 4 com-
           pares the web pages written in different language with their comparable features
           and gets similar results than Run 2 and Run 3 without the need of translation
           resources. The main advantage of this last approach is that it avoids additional
           preprocessing steps dedicated to translating the web pages, which is desirable in
           problems which have to be solved in real time. The ATMC UNED team has not
           proposed any method to group not related web pages, so their Sensitivity and
           the F-measure results are worse when considering them in the evaluation.
              The results obtained by the LSI UNED team overcome the results obtained
           by the baselines but are lower than results obtained by the ATMC UNED team.
           Going into detail, using all the words in the documents (Run 5) is under the run
           that only considers named entities and uses the same threshold (Run 2). This
           implies that the addition of all the possible words in the documents introduces
           more noise than valuable information. On the other hand, in general, if using
           named entities and increasing the threshold value, the Reliability increases while
           the Sensibility decreases. Finally, considering all web pages can be seen as a
           more difficult task, but the number of unrelated web pages in the corpus is small




                                                                                                                        123
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




                              Table 4. Evaluation results considering all the pages.


                           System and run number                     R        S        F0.5
                           ATMC UNED - run 3                         0.79     0.74     0.75
                           ATMC UNED - run 4                         0.78     0.75     0.75
                           ATMC UNED - run 1                         0.78     0.73     0.74
                           ATMC UNED - run 2                         0.82     0.69     0.73
                           LSI UNED - run 3                          0.59     0.81     0.60
                           LSI UNED - run 2                          0.52     0.92     0.59
                           LSI UNED - run 5                          0.52     0.90     0.59
                           LSI UNED - run 1                          0.49     0.97     0.58
                           LSI UNED - run 4                          0.74     0.66     0.58
                           Loz Team - run 1                          0.49     0.73     0.58
                           PanMorCresp Team - run 4                  0.52     0.86     0.58
                           Baseline - ALL-IN-ONE                     0.47     1.0      0.56
                           Loz Team - run 5                          0.50     0.80     0.54
                           Loz Team - run 3                          0.56     0.66     0.53
                           Loz Team - run 4                          0.49     0.78     0.52
                           Loz Team - run 2                          0.54     0.61     0.50
                           PanMorCresp Team - run 3                  0.53     0.81     0.50
                           PanMorCresp Team - run 2                  0.49     0.62     0.43
                           PanMorCresp Team - run 1                  0.79     0.46     0.40
                           Baseline - ONE-IN-ONE                     1.0      0.25     0.36




           and hence the results are quite similar between these two settings which use a
           threshold-based clustering approach.
               The PanMorCresp Team Run 1 and Run 2 perform about equally well re-
           gardless of whether or not related pages are taken into account in the evaluation.
           Run 1 achieves good Reliability, which fits well with the fact that complete link-
           age was used. This comes at the cost of a low Sensitivity. For Run 2, the picture
           is reversed. Run 3 and Run 4 obtain a higher score than Run 1 and Run 2.
           Punctuation removal, stop word removal and the larger vocabulary may play a
           role in this. In addition, HAC single linkage was used in both of these runs. Run
           4 is the best of the PanMorCresp Team runs; the only difference with regard to
           Run 3 is that it uses a fixed number of clusters (9) as a stopping criterion. The
           score of Run 4 beats both baselines and is on par with scores obtained with the
           other approaches save the scores obtained by the ATMC UNED runs.
               Out of the five runs submitted by the Loz Team, only Run 1 managed to
           outperform the ALL-IN-ONE baseline. The rest of the runs only managed to
           outperform the ONE-IN-ONE baseline, performing worse than the ALL-IN-ONE
           baseline. One of the main reasons why these approaches did not perform as well
           may be due to the fact that the multilingualism and overlaps between clusters
           have not been considered, posing a significant limitation for this task. Their best
           performing approach (Run 1) uses a weighted representation of words, which




                                                                                                                        124
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




           shows that considering the frequency of words in documents leads to better
           performance than the sole use of a binary representation capturing the presence
           or not of words as well as TD-IDF. They also found that considering five clusters
           as the stopping criterion, instead of 15, leads to an increased Sensitivity score,
           which is however at the expense of a little drop in Reliability.


           7     Conclusions

           The M-WePNaD shared task on Multilingual Web Person Name Disambiguation
           took place as part of the IberEval 2017 evaluation campaign. This shared task
           was the first to consider multilingualism in the person name disambiguation
           problem, following a series of WePS shared tasks where the corpora were limited
           to documents in English. The M-WePNaD shared task provided the opportunity
           for researchers to test their systems on a benchmark dataset and shared task,
           enabling comparison with one another.
               Despite a larger number of teams registering initially for the task, four of
           them managed to submit results on time, amounting to 18 different submissions.
           Only two of the four participants, namely the champions and the runners-up,
           made use of more sophisticated clustering algorithms, whereas the other two
           relied on the Hierarchical Agglomerative Clustering (HAC) algorithm. Only one
           of the teams presented an approach that does not require any prior knowledge
           to fix thresholds, which came from the team that qualified in the top position.
           We argue that this is a desirable characteristic for web page clustering, owing
           to the heterogeneous nature of the Web, which poses an additional challenge for
           learning generalizable patterns.
               With respect to the approaches used for web page representation, most of the
           teams relied on traditional techniques based on bag-of-words and vector space
           models, with the exception of the runners-up, who used word embeddings.
               While the novel aspect proposed in this shared task has been the multilin-
           gual nature of the dataset, only one team has proposed approaches that explic-
           itly tackles multilingualism, ATMC UNED, particularly it has explored three
           approaches. The results obtained for these approaches slightly outperform the
           one that does not consider multilingualism. On the other hand, the dataset also
           included web pages from social media, unlike in previous shared tasks. However,
           only one of the teams, ATMC UNED, has taken this into account when devel-
           oping their system. None of the systems has dealt with unrelated results and
           overlapping clusters.


           Acknowledgments

           This work has been part-funded by the Spanish Ministry of Science and Inno-
           vation (MAMTRA-MED Project, TIN2016-77820-C3-2-R and MED-RECORD
           Project, TIN2013-46616-C2-2-R).




                                                                                                                        125
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




           References

            1. J. Artiles, J. Gonzalo and S. Sekine. (2007). The SemEval-2007 WePS Evalua-
               tion: Establishing a Benchmark for the Web People Search Task. In Proceedings
               of the Fourth International Workshop on Semantic Evaluations (SemEval-2007),
               pages 64–69, Prague, Czech Republic, June 2007. Association for Computational
               Linguistics.
            2. J. Artiles, J. Gonzalo and S. Sekine. (2009) Weps 2 Evaluation Campaign: Overview
               of the Web People Search Clustering Task. In 2nd Web People Search Evaluation
               Workshop (WePS 2009), 18th WWW Conference, 2009.
            3. J. Artiles, A. Borthwick, J. Gonzalo, S. Sekine and E. Amigó. (2010). WePS-3 Eval-
               uation Campaign: Overview of the Web People Search Clustering and Attribute
               Extraction Tasks. In Third Web People Search Evaluation Forum (WePS-3), CLEF
               2010.
            4. R. Berendsen, Finding people, papers, and posts: Vertical search algorithms and
               evaluation, Ph.D. thesis, Informatics Institute, University of Amsterdam (2015).
               URL: http://dare.uva.nl/document/2/165379
            5. S. Montalvo, R. Martı́nez, L. Campillos, A. D. Delgado, V. Fresno, F. Verdejo.
               MC4WePS: a multilingual corpus for web people search disambiguation, Lan-
               guage Resources and Evaluation (2016). URL: http://dx.doi.org/10.1007/s10579-
               016-9365-4.
            6. E. Amigó, J. Gonzalo, F. Verdejo. A General Evaluation Measure for Document Or-
               ganization Tasks. In Proceedings of the 36th International ACM SIGIR Conference
               on Research and Development in Information Retrieval (SIGIR 2013), pp. 643-652.
               Dublin, Ireland, 2013. URL: http://doi.acm.org/10.1145/2484028.2484081.
            7. A. Bagga, B. Baldwin, Entity-based cross-document coreferencing using
               the vector space model. In Proceedings of the 17th International Confer-
               ence on Computational Linguistics - Volume 1, COLING’98, Association for
               Computational Linguistics, Stroudsburg, PA, USA, 1998, pp. 79-85. URL
               http://dx.doi.org/10.3115/980451.980859.
            8. A. Delgado. ATMC team at M-WePNaD task. In: Proceedings of the Second
               Workshop on Evaluation of Human Language Technologies for Iberian Languages
               (IberEval 2017), Murcia, Spain, September 19, CEUR Workshop Proceedings.
               CEUR-WS.org, 2017
            9. A.D. Delgado, R. Martı́nez, S. Montalvo and V. Fresno. Person Name
               Disambiguation in the Web Using Adaptive Threshold Clustering. Jour-
               nal of the Association for Information Science and Technology, 2017. URL:
               https://doi.org/10.1002/asi.23810.
           10. A.D. Delgado: Desambiguacion de nombres de persona en la Web en un contexto
               multilingüe. PhD Thesis, E.T.S. Ingenierı́a Informática, UNED, 2017.
           11. A.D. Delgado, R. Martı́nez, S. Montalvo and V. Fresno. Tratamiento
               de redes sociales en desambiguación de nombres de persona en la
               web. Procesamiento del Lenguaje Natural, 57:117-124, 2016. URL:
               http://journal.sepln.org/sepln/ojs/ojs/index.php/pln/article/view/5344.
           12. A. Duque, L. Araujo and J. Martı́nez-Romo. LSI UNED at M-WePNaD: Embed-
               dings for Person Name Disambiguation. In: Proceedings of the Second Workshop
               on Evaluation of Human Language Technologies for Iberian Languages (IberEval
               2017), Murcia, Spain, September 19, CEUR Workshop Proceedings. CEUR-
               WS.org, 2017




                                                                                                                        126
Proceedings of the Second Workshop on Evaluation of Human Language Technologies for Iberian Languages (IberEval 2017)




           13. L. Lozano, Jorge Carrillo-de-Albornoz and E. Amigó. UNED Loz Team at M-
               WePNaD. In: Proceedings of the Second Workshop on Evaluation of Human Lan-
               guage Technologies for Iberian Languages (IberEval 2017), Murcia, Spain, Septem-
               ber 19, CEUR Workshop Proceedings. CEUR-WS.org, 2017
           14. P. Panero, M. Moreno, T. Crespo, Jorge Carrillo-de-Albornoz and E. Amigó.
               UNED PanMorCrepsTeam at M-WePNaD. In: Proceedings of the Second Workshop
               on Evaluation of Human Language Technologies for Iberian Languages (IberEval
               2017), Murcia, Spain, September 19, CEUR Workshop Proceedings. CEUR-
               WS.org, 2017




                                                                                                                        127