=Paper= {{Paper |id=Vol-2721/paper521 |storemode=property |title=Leveraging Multilingual Descriptions for Link Prediction: Initial Experiments |pdfUrl=https://ceur-ws.org/Vol-2721/paper521.pdf |volume=Vol-2721 |authors=Genet Asefa Gesese,Fabian Hoppe,Mehwish Alam,Harald Sack |dblpUrl=https://dblp.org/rec/conf/semweb/GeseseHAS20 }} ==Leveraging Multilingual Descriptions for Link Prediction: Initial Experiments== https://ceur-ws.org/Vol-2721/paper521.pdf
    Leveraging Multilingual Descriptions for Link
           Prediction: Initial Experiments

Genet Asefa Gesese1,2 , Mehwish Alam1,2 , Fabian Hoppe1,2 , and Harald Sack1,2
    1
        FIZ Karlsruhe – Leibniz Institute for Information Infrastructure, Germany
            2
              Karlsruhe Institute of Technology, Institute AIFB, Germany
                       firstname.lastname@fiz-karlsruhe.de



        Abstract. In most Knowledge Graphs (KGs), textual descriptions of
        entities are provided in multiple natural languages. Additional informa-
        tion that is not explicitly represented in the structured part of the KG
        might be available in these textual descriptions. Link prediction models
        which make use of entity descriptions usually consider only one language.
        However, descriptions given in multiple languages may provide comple-
        mentary information which should be taken into consideration for the
        tasks such as link prediction. In this poster paper, the benefits of mul-
        tilingual embeddings for incorporating multilingual entity descriptions
        into the task of link prediction in KGs are investigated.




1    Introduction
Various Knowledge Graphs (KGs) such as DBpedia and Wikidata have been
published to share linked data and have been crucial for many tasks. However,
according to the Open World Assumption, KGs are never complete. Due to this
fact, different KG completion models which map KGs to a low dimensional vec-
tor space based on the task of link prediction have been proposed. However,
only some of these models such as DKRL [10], MKBE[7] , Jointly[11] , SSP [9]
, and LiteralE [6] leverage the textual descriptions of entities for the link pre-
diction task [4]. Furthermore, most popular KGs contain descriptions in two or
more languages for a single entity due to the multilingual community working
on these KGs (as in Wikidata) or the multilingual nature of its sources (as in
DBpedia). The cultural context and bias associated with each of these descrip-
tions induces a difference with regards to content. However, despite the fact that
entity descriptions are available in multiple natural languages, all the existing
models including DKRL consider only one language. Figure 1 presents an exam-
ple scenario showing the differences in contents of multilingual descriptions of a
single entity. In this example, the description in German contains information
which does not appear in the English or French descriptions. For instance, the
fact that the team is the record winner of the U-19 Asian Cup with twelve titles
is only mentioned in the German description.




Copyright © 2020 for this paper by its authors. Use permitted under Creative Com-
mons License Attribution 4.0 International (CC BY 4.0).
    This paper presents part of an ongoing work which is an empirical evaluation
of an already published position paper [3]. Specifically, in this poster paper, the
performance of the existing model DKRL in leveraging multilingual descriptions
using multilingual embeddings has been analysed and the results of the initial
experiments are discussed.


”Die südkoreanische U-20-Fußballnationalmannschaft ist ... bei U-20-
Weltmeisterschaften und U-19-Asienmeisterschaften...”@de
                                /m/05f5sr9 (”South Korea na-
                                tional under-20 football team”)
    ”L’équipe de Corée du Sud de                  ”The Korea Republic national
    football des moins de 20 ... de la              under-20 football team repre-
    Fédération de Corée du Sud de                sents South Korea in international
    football (KFA).@fr).                            youth football competitions.”@en

Fig. 1: An entity from Freebase with descriptions from its corresponding English,
German, and French Wikipedia pages. For instance, the description in German
provides more content that is not in the descriptions of either the English or the
French Pages.




2      Multilingual Word Embeddings

As discussed in [3], an entity alignment model named KDCoE [2] has demon-
strated the advantage of multilingual word embeddings by using a cross-lingual
Bilbowa word embedding [5] to encode multilingual descriptions for the task of
cross lingual learning. In this paper, the same approach is adopted to encode mul-
tilingual entity descriptions for a link prediction task on a monolingual dataset.
In particular, the experiments have been performed with one of the existing
models DKRL [10] using pretrained multilingual word embeddings by MUSE3 .
DKRL is an extension of TransE [1], which learns two kinds of vector represen-
tations for an entity, i.e., structure-based and description-based representations.
DKRL adopts TransE for the structure-based representation and uses CNN to
encode entity descriptions for the description-based representations. These two
kinds of entity representations are learned simultaneously into the same vector
space without forcing them to be unified. In our experiments, in order to ef-
fectively utilize multilingual descriptions, the embeddings of the words in the
descriptions obtained by MUSE are passed as inputs to the encoder.
    MUSE has been chosen because this paper deals with multilingual descrip-
tions and MUSE aligns embeddings (specifically, FastText embeddings) of words
3
    https://github.com/facebookresearch/MUSE
in different languages into the same vector space. Figure 2 shows the CNN en-
coder part of DKRL with pretrained word embeddings from multilingual de-
scriptions as inputs.




Fig. 2: Passing pretrained multilingual word embeddings to a CNN encoder which
is adopted from DKRL [10] and shown in [3], in order to encode multilingual
entity descriptions.




3     Experimental Evaluation

In this section, the experiments conducted to incorporate textual descriptions
in English, French, and German into DKRL (for the task of link prediction)
are presented. Table 1 shows the dataset created out of FB15K-237 [8] for the
experiments by removing those triples for which either the head or tail entity
does not have descriptions in at least one of the three languages mentioned
above or have less than 3 words after preprocessing. Since FB15K-237 is a
dataset generated from Freebase and the entity descriptions in Freebase are
old, the descriptions in all the three languages have been constructed by tak-
ing the information from the summary part of their respective Wikipedia pages.
During preprocessing, stop words are removed and all phrases are marked us-
ing entity names and also by applying Spacy’s4 named entity recognizer. The
created dataset is available at https://github.com/ISE-FIZKarlsruhe/Link-
Prediction-with-Multilingual-Entity-Descriptions.
    For the experiments with DKRL and TransE, the code published at https:
//github.com/xrb92/DKRL by the authors of the DKRL paper and the code
4
    https://spacy.io/
for TransE available at https://github.com/thunlp/OpenKE has been used
respectively. The DKRL model has been trained on three varieties of the dataset,
given the names DKRLe , DKRLeg , and DKRLegf . For DKRLe , only English
descriptions are used whereas for DKRLeg the combination of descriptions in
German and English are used. On the other hand, descriptions in all the three
languages are used to train DKRLegf . The minimum, maximum, and average
number of words are 3, 615, and 107.351 for the descriptions in DKRLe , 9, 970,
and 140.591 in DKRLeg , and 18, 1460, and 192.091 in DKRLegf respectively.
    In DKRLe , the words are initialized using FastText pretrained embeddings
and for the other two models MUSE pretrained embeddings are used. As shown
in Table 2, TransE [1] has also been trained on the new dataset for fair compari-
son with DKRL. The hyperparameters are chosen from embedding size {50, 100,
150}, margin {1.0, 2.0, 3.0, 4.0, 5.0}, learning rate {0.01, 0.1, 1.0} (following the
same procedure as in the paper of TransE). The optimal parameters for TransE
on this dataset is embedding size: 100, margin: 4.0, learning rate: 0.1, and epoch:
1000. For all the other models DKRLe , DKRLeg , and DKRLegf , the same proce-
dure as in the original study DKRL has been adopted. The optimal parameters
are entity and relation embedding size: 100, learning rate 0.001, margin: 1.0,
window-size: 2, dimension of feature map: 100, and word embedding size: 300,
for all the three varieties. DKRLe is trained for 1000 epochs where as DKRLeg
and DKRLegf are trained for 1200 epochs.
    As shown in Table 2, incorporating descriptions into the link prediction task
brings improvement over TransE. However, when comparing the different vari-
eties of DKRL, it is seen that combining multiple descriptions has only a slight
improvement. For instance, hits@10 is the same for DKRLeg and DKRLegf . One
potential reason for such results could be the out of vocabulary words in the pre-
trained word embeddings by MUSE. There are 18.4% and 20% out of vocabulary
words for DKRLeg and DKRLegf respectively and they are randomly initialized.



Table 1: The statistics of the          Table 2: Experiment results using
dataset used for the experiments.       transE and DKRL models on the differ-
         FB15K-237                      ent varieties of the FB15K-237 dataset.
#Ent        12729                               MR MRR Hits@1 Hits@3 Hits@10
 #Rel        234                        TransE 213 0.266 0.175 0.297 0.448
#Train     219573                       DKRLe 201 0.275 0.189 0.304 0.449
#Valid      13919                       DKRLeg 185 0.280 0.191 0.310 0.457
#Test       16084                       DKRLegf 180 0.285 0.196 0.311 0.457



4   Conclusion and Future Work
In this paper, which is based on an already published position paper, preliminary
results from an ongoing work to discuss the benefits of leveraging multilingual
embeddings for the task of link prediction are presented. As a future work,
more experiments will be conducted by aligning pretrained FastText embeddings
which have bigger vocabulary size, using MUSE, to avoid the problem which
rises due to out of vocabulary words. Moreover, another way to improve the
results will be investigated which is to learn description-based embeddings of an
entity separately for each language and then fusing the vectors using different
approaches.


References
 1. Bordes, A., Usunier, N., Garcia-Duran, A., Weston, J., Yakhnenko, O.: Translating
    Embeddings for Modeling Multi-Relational Data. In: NIPS (2013)
 2. Chen, M., Tian, Y., Chang, K.W., Skiena, S., Zaniolo, C.: Co-training embeddings
    of knowledge graphs and entity descriptions for cross-lingual entity alignment.
    arXiv preprint arXiv:1806.06478 (2018)
 3. Gesese, G.A., Alam, M., Sack, H.: Semantic entity enrichment by leveraging mul-
    tilingual descriptions for link prediction. In: DL4KG@ ESWC (2020)
 4. Gesese, G.A., Biswas, R., Alam, M., Sack, H.: A survey on knowledge graph
    embeddings with literals: Which model links better literal-ly? arXiv preprint
    arXiv:1910.12507 (2019)
 5. Gouws, S., Bengio, Y., Corrado, G.: Bilbowa: Fast bilingual distributed represen-
    tations without word alignments. In: ICML (2015)
 6. Kristiadi, A., Khan, M.A., Lukovnikov, D., Lehmann, J., Fischer, A.: Incorpo-
    rating literals into knowledge graph embeddings. In: International Semantic Web
    Conference. pp. 347–363. Springer (2019)
 7. Pezeshkpour, P., Chen, L., Singh, S.: Embedding multimodal relational data for
    knowledge base completion. In: Proceedings of the 2018 Conference on Empirical
    Methods in Natural Language Processing. pp. 3208–3218. Association for Compu-
    tational Linguistics (Oct-Nov 2018), https://www.aclweb.org/anthology/D18-
    1359
 8. Toutanova, K., Chen, D.: Observed versus latent features for knowledge base and
    text inference. In: 3rd Workshop on Continuous Vector Space Models and their
    Compositionality. Association for Computational Linguistics (2015)
 9. Xiao, H., Huang, M., Meng, L., Zhu, X.: Ssp: semantic space projection for knowl-
    edge graph embedding with text descriptions. In: Thirty-First AAAI Conference
    on Artificial Intelligence (2017)
10. Xie, R., Liu, Z., Jia, J., Luan, H., Sun, M.: Representation learning of knowledge
    graphs with entity descriptions. In: AAAI (2016)
11. Xu, J., Qiu, X., Chen, K., Huang, X.: Knowledge graph representation
    with jointly structural and textual encoding. pp. 1318–1324 (08 2017).
    https://doi.org/10.24963/ijcai.2017/183