Multi-Language Neural Network Model with Advance Preprocessor for Gender Classification over Social Media

This paper describes approaches for the Author Profiling Shared Task at PAN 2018. The goal was to classify the gender of a Twitter user solely by their tweets. Paper explores a simple and efficient Multi-Language model for gender classification. The approach consists of tweet preprocessing, text representation and classification model construction. The model achieved the best results on the English language with an accuracy of 72.79%; for the Spanish and Arabic languages the accuracy was 72.20% and 64.36%, respectively

Arabic tweeps dialect prediction based on machine learning approach

In this paper, we present our approach for profiling Arabic authors on twitter, based on their tweets. We consider here the dialect of an Arabic author as an important trait to be predicted. For this purpose, many indicators, feature vectors and machine learning-based classifiers were implemented. The results of these classifiers were compared to find out the best dialect prediction model. The best dialect prediction model was obtained using random forest classifier with full forms and their stems as feature vector

Fine-Grained Analysis of Language Varieties and Demographics

[EN] The rise of social media empowers people to interact and communicate with anyone anywhere in the world. The possibility of being anonymous avoids censorship and enables freedom of expression. Nevertheless, this anonymity might lead to cybersecurity issues, such as opinion spam, sexual harassment, incitement to hatred or even terrorism propaganda. In such cases, there is a need to know more about the anonymous users and this could be useful in several domains beyond security and forensics such as marketing, for example. In this paper, we focus on a fine-grained analysis of language varieties while considering also the authors¿ demographics. We present a Low-Dimensionality Statistical Embedding method to represent text documents. We compared the performance of this method with the best performing teams in the Author Profiling task at PAN 2017. We obtained an average accuracy of 92.08% versus 91.84% for the best performing team at PAN 2017. We also analyse the relationship of the language variety identification with the authors¿ gender. Furthermore, we applied our proposed method to a more fine-grained annotated corpus of Arabic varieties covering 22 Arab countries and obtained an overall accuracy of 88.89%. We have also investigated the effect of the authors¿ age and gender on the identification of the different Arabic varieties, as well as the effect of the corpus size on the performance of our method.This publication was made possible by NPRP grant 9-175-1-033 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Rangel, F.; Rosso, P.; Zaghouani, W.; Charfi, A. (2020). Fine-Grained Analysis of Language Varieties and Demographics. Natural Language Engineering. 26(6):641-661. https://doi.org/10.1017/S1351324920000108S641661266Kestemont, M. , Tschuggnall, M. , Stamatatos, E. , Daelemans, W. , Specht, G. , Stein, B. and Potthast, M. (2018). Overview of the Author Identification Task at PAN-2018: Cross-domain Authorship Attribution and Style Change Detection. CLEF 2018 Labs and Workshops, Notebook Papers. CEUR Workshop Proceedings. CEUR-WS.org.McNemar, Q. (1947). Note on the sampling error of the difference between correlated proportions or percentages. Psychometrika, 12(2), 153-157. doi:10.1007/bf02295996Lui, M. and Cook, P. (2013). Classifying english documents by national dialect. In Proceedings of the Australasian Language Technology Association Workshop, Citeseer pp. 5–15.Basile, A. , Dwyer, G. , Medvedeva, M. , Rawee, J. , Haagsma, H. and Nissim, M. (2017). Is there life beyond n-grams? A simple SVM-based author profiling system. In Cappellato L., Ferro N., Goeuriot L. and Mandl T. (eds), CLEF 2017 Working Notes. CEUR Workshop Proceedings (CEUR-WS.org), ISSN 1613-0073, http://ceur-ws.org/Vol-/. CLEF and CEUR-WS.org.Elfardy, H. and Diab, M.T. (2013). Sentence level dialect identification in arabic. In Association for Computational Linguistics (ACL), pp. 456–461.Salton, G., & Buckley, C. (1988). Term-weighting approaches in automatic text retrieval. Information Processing & Management, 24(5), 513-523. doi:10.1016/0306-4573(88)90021-0Zaghouani, W. and Charfi, A. (2018a). ArapTweet: A large MultiDialect Twitter corpus for gender, age and language variety identification. In Proceedings of the 11th International Conference on Language Resources and Evaluation (LREC), Miyazaki, Japan.Zampieri, M. , Tan, L. , Ljubešić, N. , Tiedemann, J. and Nakov, P. (2015). Overview of the DSL shared task 2015. In Proceedings of the Joint Workshop on Language Technology for Closely Related Languages, Varieties and Dialects, pp. 1–9.Huang, C.-R. and Lee, L.-H. (2008). Contrastive approach towards text source classification based on top-bag-of-word similarity. In PACLIC, pp. 404–410.Zaidan, O. F., & Callison-Burch, C. (2014). Arabic Dialect Identification. 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Overview of the Author Obfuscation Task at PAN 2018. CLEF 2018 Labs and Workshops, Notebook Papers. CEUR Workshop Proceedings. CEUR-WS.org.Zampieri, M. and Gebre, B.G. (2012). Automatic identification of language varieties: The case of portuguese. In The 11th Conference on Natural Language Processing (KONVENS), pp. 233–237 (2012)Rangel, F. , Rosso, P. , Montes-y-Gómez, M. , Potthast, M. and Stein, B. (2018). Overview of the 6th Author Profiling Task at PAN 2018: Multimodal Gender Identification in Twitter. In CLEF 2018 Labs and Workshops, Notebook Papers. CEUR Workshop Proceedings. CEUR-WS.org.Heitele, D. (1975). An epistemological view on fundamental stochastic ideas. Educational Studies in Mathematics, 6(2), 187-205. doi:10.1007/bf00302543Inches, G. and Crestani, F. (2012). Overview of the International Sexual Predator Identification Competition at PAN-2012. CLEF Online working notes/labs/workshop, vol. 30.Rosso, P. , Rangel Pardo, F.M. , Ghanem, B. and Charfi, A. (2018b). ARAP: Arabic Author Profiling Project for Cyber-Security. Sociedad Española para el Procesamiento del Lenguaje Natural (SEPLN).Agić, Ž. , Tiedemann, J. , Dobrovoljc, K. , Krek, S. , Merkler, D. , Može, S. , Nakov, P. , Osenova, P. and Vertan, C. (2014). Proceedings of the EMNLP 2014 Workshop on Language Technology for Closely Related Languages and Language Variants. Association for Computational Linguistics.Sadat, F., Kazemi, F., & Farzindar, A. (2014). Automatic Identification of Arabic Language Varieties and Dialects in Social Media. Proceedings of the Second Workshop on Natural Language Processing for Social Media (SocialNLP). doi:10.3115/v1/w14-5904Franco-Salvador, M., Rangel, F., Rosso, P., Taulé, M., & Antònia Martít, M. (2015). Language Variety Identification Using Distributed Representations of Words and Documents. Experimental IR Meets Multilinguality, Multimodality, and Interaction, 28-40. doi:10.1007/978-3-319-24027-5_3Rosso, P., Rangel, F., Farías, I. H., Cagnina, L., Zaghouani, W., & Charfi, A. (2018). A survey on author profiling, deception, and irony detection for the Arabic language. Language and Linguistics Compass, 12(4), e12275. doi:10.1111/lnc3.12275Malmasi, S. , Zampieri, M. , Ljubešić, N. , Nakov, P. , Ali, A. and Tiedemann, J. (2016). Discriminating between similar languages and arabic dialect identification: A report on the third DSL shared task. In Proceedings of the Third Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial3), pp. 1–14.Rangel, F. , Rosso, P. , Potthast, M. and Stein, B. (2017). Overview of the 5th Author Profiling Task at PAN 2017: Gender and Language Variety Identification in Twitter. In Cappellato L., Ferro N., Goeuriot, L. and Mandl T. (eds), Working Notes Papers of the CLEF 2017 Evaluation Labs, p. 1613–0073, CLEF and CEUR-WS.org.Zampieri, M. , Malmasi, S. , Ljubešić, N. , Nakov, P. , Ali, A. , Tiedemann, J. , Scherrer, Y. , Aepli, N. (2017). Findings of the vardial evaluation campaign 2017. In Proceedings of the Fourth Workshop on NLP for Similar Languages, Varieties and Dialects, pp. 1–15.Bogdanova, D., Rosso, P., & Solorio, T. (2014). Exploring high-level features for detecting cyberpedophilia. Computer Speech & Language, 28(1), 108-120. doi:10.1016/j.csl.2013.04.007Maier, W. and Gómez-Rodríguez, C. (2014). Language Variety Identification in Spanish Tweets. LT4CloseLang.Castro, D. , Souza, E. , de Oliveira, A.L.I. (2016). Discriminating between Brazilian and European Portuguese national varieties on Twitter texts. In 5th Brazilian Conference on Intelligent Systems (BRACIS), pp. 265–270.Zaghouani, W. and Charfi, A. (2018b). Guidelines and annotation framework for Arabic author profiling. 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Overview of PAN 2018. Author identification, author profiling, and author obfuscation

[EN] PAN 2018 explores several authorship analysis tasks enabling a systematic comparison of competitive approaches and advancing research in digital text forensics.More specifically, this edition of PAN introduces a shared task in cross-domain authorship attribution, where texts of known and unknown authorship belong to distinct domains, and another task in style change detection that distinguishes between single author and multi-author texts. In addition, a shared task in multimodal author profiling examines, for the first time, a combination of information from both texts and images posted by social media users to estimate their gender. Finally, the author obfuscation task studies how a text by a certain author can be paraphrased so that existing author identification tools are confused and cannot recognize the similarity with other texts of the same author. New corpora have been built to support these shared tasks. A relatively large number of software submissions (41 in total) was received and evaluated. Best paradigms are highlighted while baselines indicate the pros and cons of submitted approaches.The work at the Universitat Polit`ecnica de Val`encia was funded by the MINECO research project SomEMBED (TIN2015-71147-C2-1-P)Stamatatos, E.; Rangel-Pardo, FM.; Tschuggnall, M.; Stein, B.; Kestemont, M.; Rosso, P.; Potthast, M. (2018). Overview of PAN 2018. Author identification, author profiling, and author obfuscation. Lecture Notes in Computer Science. 11018:267-285. https://doi.org/10.1007/978-3-319-98932-7_25S26728511018Argamon, S., Juola, P.: Overview of the international authorship identification competition at PAN-2011. In: Petras, V., Forner, P., Clough, P. (eds.) Notebook Papers of CLEF 2011 Labs and Workshops, 19–22 September 2011, Amsterdam, Netherlands, September 2011. http://www.clef-initiative.eu/publication/working-notesBird, S., Klein, E., Loper, E.: Natural Language Processing with Python. O’Reilly Media, Sebastopol (2009)Bogdanova, D., Lazaridou, A.: Cross-language authorship attribution. In: Proceedings of the 9th International Conference on Language Resources and Evaluation, LREC 2014, pp. 2015–2020 (2014)Choi, F.Y.: Advances in domain independent linear text segmentation. In: Proceedings of the 1st North American Chapter of the Association for Computational Linguistics Conference (NAACL), pp. 26–33. Association for Computational Linguistics, Seattle, April 2000Custódio, J.E., Paraboni, I.: EACH-USP ensemble cross-domain authorship attribution. In: Working Notes Papers of the CLEF 2018 Evaluation Labs, September 2018, to be announcedDaneshvar, S.: Gender identification in Twitter using n-grams and LSA. In: Working Notes Papers of the CLEF 2018 Evaluation Labs, September 2018, to be announcedDaniel Karaś, M.S., Sobecki, P.: OPI-JSA at CLEF 2017: author clustering and style breach detection. In: Working Notes Papers of the CLEF 2017 Evaluation Labs. CEUR Workshop Proceedings. CLEF and CEUR-WS.org, September 2017Giannella, C.: An improved algorithm for unsupervised decomposition of a multi-author document. The MITRE Corporation. Technical Papers, February 2014Glover, A., Hirst, G.: Detecting stylistic inconsistencies in collaborative writing. In: Sharples, M., van der Geest, T. (eds.) The New Writing Environment, pp. 147–168. Springer, London (1996). https://doi.org/10.1007/978-1-4471-1482-6_12Hagen, M., Potthast, M., Stein, B.: Overview of the author obfuscation task at PAN 2017: safety evaluation revisited. In: Cappellato, L., Ferro, N., Goeuriot, L., Mandl, T. (eds.) Working Notes Papers of the CLEF 2017 Evaluation Labs. CEUR Workshop Proceedings, CLEF and CEUR-WS.org, September 2017Hagen, M., Potthast, M., Stein, B.: Overview of the author obfuscation task at PAN 2018. In: Working Notes Papers of the CLEF 2018 Evaluation Labs. CEUR Workshop Proceedings, CLEF and CEUR-WS.org (2018)Hellekson, K., Busse, K. (eds.): The Fan Fiction Studies Reader. University of Iowa Press, Iowa City (2014)Juola, P.: An overview of the traditional authorship attribution subtask. In: Forner, P., Karlgren, J., Womser-Hacker, C. (eds.) CLEF 2012 Evaluation Labs and Workshop - Working Notes Papers, 17–20 September 2012, Rome, Italy, September 2012. http://www.clef-initiative.eu/publication/working-notesJuola, P.: The rowling case: a proposed standard analytic protocol for authorship questions. Digital Sch. Humanit. 30(suppl–1), i100–i113 (2015)Kestemont, M., Luyckx, K., Daelemans, W., Crombez, T.: Cross-genre authorship verification using unmasking. Engl. Stud. 93(3), 340–356 (2012)Kestemont, M., et al.: Overview of the author identification task at PAN-2018: cross-domain authorship attribution and style change detection. In: Working Notes Papers of the CLEF 2018 Evaluation Labs. CEUR Workshop Proceedings, CLEF and CEUR-WS.org (2018)Koppel, M., Schler, J., Bonchek-Dokow, E.: Measuring differentiability: unmasking pseudonymous authors. J. Mach. Learn. Res. 8, 1261–1276 (2007)Overdorf, R., Greenstadt, R.: Blogs, Twitter feeds, and reddit comments: cross-domain authorship attribution. Proc. Priv. Enhanc. Technol. 2016(3), 155–171 (2016)Pedregosa, F., et al.: Scikit-learn: machine learning in Python. J. Mach. Learn. Res. 12, 2825–2830 (2011)Potthast, M., Eiselt, A., Barrón-Cedeño, A., Stein, B., Rosso, P.: Overview of the 3rd international competition on plagiarism detection. In: Notebook Papers of the 5th Evaluation Lab on Uncovering Plagiarism, Authorship and Social Software Misuse (PAN), Amsterdam, The Netherlands, September 2011Potthast, M., Hagen, M., Stein, B.: Author obfuscation: attacking the state of the art in authorship verification. In: Working Notes Papers of the CLEF 2016 Evaluation Labs. CEUR Workshop Proceedings, CLEF and CEUR-WS.org, September 2016. http://ceur-ws.org/Vol-1609/Potthast, M., Hagen, M., Völske, M., Stein, B.: Crowdsourcing interaction logs to understand text reuse from the web. In: Fung, P., Poesio, M. (eds.) Proceedings of the 51st Annual Meeting of the Association for Computational Linguistics (ACL 2013), pp. 1212–1221. Association for Computational Linguistics, August 2013. http://www.aclweb.org/anthology/P13-1119Rangel, F., Celli, F., Rosso, P., Potthast, M., Stein, B., Daelemans, W.: Overview of the 3rd author profiling task at PAN 2015. In: Cappellato, L., Ferro, N., Jones, G., San Juan, E. (eds.) CLEF 2015 Evaluation Labs and Workshop - Working Notes Papers, Toulouse, France, pp. 8–11. CEUR-WS.org, September 2015Rangel, F., et al.: Overview of the 2nd author profiling task at PAN 2014. In: Cappellato, L., Ferro, N., Halvey, M., Kraaij, W. (eds.) CLEF 2014 Evaluation Labs and Workshop - Working Notes Papers, Sheffield, UK, pp. 15–18. CEUR-WS.org, September 2014Rangel, F., Rosso, P., G’omez, M.M., Potthast, M., Stein, B.: Overview of the 6th author profiling task at pan 2018: multimodal gender identification in Twitter. In: CLEF 2018 Labs and Workshops, Notebook Papers. CEUR Workshop Proceedings. CEUR-WS.org (2017)Rangel, F., Rosso, P., Koppel, M., Stamatatos, E., Inches, G.: Overview of the author profiling task at PAN 2013. In: Forner, P., Navigli, R., Tufis, D. (eds.) CLEF 2013 Evaluation Labs and Workshop - Working Notes Papers, 23–26 September 2013, Valencia, Spain, September 2013Rangel, F., Rosso, P., Potthast, M., Stein, B.: Overview of the 5th author profiling task at PAN 2017: gender and language variety identification in Twitter. In: Cappellato, L., Ferro, N., Goeuriot, L., Mandl, T. (eds.) Working Notes Papers of the CLEF 2017 Evaluation Labs. CEUR Workshop Proceedings, CLEF and CEUR-WS.org, September 2017Rangel, F., Rosso, P., Verhoeven, B., Daelemans, W., Potthast, M., Stein, B.: Overview of the 4th author profiling task at PAN 2016: cross-genre evaluations. In: Balog, K., Cappellato, L., Ferro, N., Macdonald, C. (eds.) CLEF 2016 Labs and Workshops, Notebook Papers. CEUR Workshop Proceedings. CEUR-WS.org, September 2016Safin, K., Kuznetsova, R.: Style breach detection with neural sentence embeddings. In: Working Notes Papers of the CLEF 2017 Evaluation Labs. CEUR Workshop Proceedings, CLEF and CEUR-WS.org, September 2017Sapkota, U., Bethard, S., Montes, M., Solorio, T.: Not all character n-grams are created equal: a study in authorship attribution. In: Proceedings of the 2015 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, pp. 93–102 (2015)Sapkota, U., Solorio, T., Montes, M., Bethard, S., Rosso, P.: Cross-topic authorship attribution: will out-of-topic data help? In: Proceedings of the 25th International Conference on Computational Linguistics. Technical Papers, pp. 1228–1237 (2014)Stamatatos, E.: Intrinsic plagiarism detection using character $$n$$n-gram Profiles. In: Stein, B., Rosso, P., Stamatatos, E., Koppel, M., Agirre, E. (eds.) SEPLN 2009 Workshop on Uncovering Plagiarism, Authorship, and Social Software Misuse (PAN 2009), pp. 38–46. Universidad Politécnica de Valencia and CEUR-WS.org, September 2009. http://ceur-ws.org/Vol-502Stamatatos, E.: On the robustness of authorship attribution based on character n-gram features. J. Law Policy 21, 421–439 (2013)Stamatatos, E.: Authorship attribution using text distortion. In: Proceedings of the 15th Conference of the European Chapter of the Association for Computational Linguistics, Long Papers, vol. 1, pp. 1138–1149. Association for Computational Linguistics (2017)Stamatatos, E., et al.: Overview of the author identification task at PAN 2015. In: Cappellato, L., Ferro, N., Jones, G., San Juan, E. (eds.) CLEF 2015 Evaluation Labs and Workshop - Working Notes Papers, 8–11 September 2015, Toulouse, France. CEUR-WS.org, September 2015Stamatatos, E., et al.: Clustering by authorship within and across documents. In: Working Notes Papers of the CLEF 2016 Evaluation Labs. CEUR Workshop Proceedings, CLEF and CEUR-WS.org, September 2016. http://ceur-ws.org/Vol-1609/Takahashi, T., Tahara, T., Nagatani, K., Miura, Y., Taniguchi, T., Ohkuma, T.: Text and image synergy with feature cross technique for gender identification. In: Working Notes Papers of the CLEF 2018 Evaluation Labs, September 2018, to be announcedTellez, E.S., Miranda-Jiménez, S., Moctezuma, D., Graff, M., Salgado, V., Ortiz-Bejar, J.: Gender identification through multi-modal tweet analysis using microtc and bag of visual words. In: Working Notes Papers of the CLEF 2018 Evaluation Labs, September 2018, to be announcedTschuggnall, M., Specht, G.: Automatic decomposition of multi-author documents using grammar analysis. In: Proceedings of the 26th GI-Workshop on Grundlagen von Datenbanken. CEUR-WS, Bozen, October 2014Tschuggnall, M., et al.: Overview of the author identification task at PAN-2017: style breach detection and author clustering. In: Cappellato, L., Ferro, N., Goeuriot, L., Mandl, T. (eds.) Working Notes Papers of the CLEF 2017 Evaluation Labs. CEUR Workshop Proceedings, vol. 1866. CLEF and CEUR-WS.org, September 2017. http://ceur-ws.org/Vol-1866

What demographic attributes do our digital footprints reveal? A systematic review

<div><p>To what extent does our online activity reveal who we are? Recent research has demonstrated that the digital traces left by individuals as they browse and interact with others online may reveal who they are and what their interests may be. In the present paper we report a systematic review that synthesises current evidence on predicting demographic attributes from online digital traces. Studies were included if they met the following criteria: (i) they reported findings where at least one demographic attribute was predicted/inferred from at least one form of digital footprint, (ii) the method of prediction was automated, and (iii) the traces were either visible (e.g. tweets) or non-visible (e.g. clickstreams). We identified 327 studies published up until October 2018. Across these articles, 14 demographic attributes were successfully inferred from digital traces; the most studied included gender, age, location, and political orientation. For each of the demographic attributes identified, we provide a database containing the platforms and digital traces examined, sample sizes, accuracy measures and the classification methods applied. Finally, we discuss the main research trends/findings, methodological approaches and recommend directions for future research.</p></div

Classificação Supervisionada de Documentos de Texto Cru em contextos difíceis

A classificação de documentos é uma área com cada vez mais aplicações. Naturalmente, o número de estudos produzidos tem vindo assim a aumentar e, consequentemente as propostas e abordagens aos diversos problemas têm vindo a melhorar. A classificação de documentos ramifica-se também pelas diferentes abordagens a cada problema, uma vez que estas abordagens diferem consoante a forma como os dados são apresentados. Os resultados obtidos por cada método apresentam por norma diferenças em termos de precisão. De forma genérica, a classificação supervisionada permite obter resultados melhores em comparação com a classificação não supervisionada, onde a priori os dados não têm uma classe conhecida. Neste sentido, quer a Atribuição de Autoria quer a Verificação de Plágio fazem parte da classificação de documentos. Embora com objetivos fundamentalmente diferentes, ambas têm como objetivo inferir a partir do conjunto de dados que compõem um documento, informação sobre o seu autor. Para a realização da presente dissertação, pretende-se desenvolver um sistema capaz de realizar a atribuição de autoria, mas também o de rejeitar um documento que seja muito dissemelhante de qualquer dos protótipos aprendidos numa fase de treino. Ou seja, o sistema recebe um conjunto de amostras (documentos) produzidos por cada autor, extrai informação útil que represente cada um e após uma fase de treino, recebe novos documentos e tenta atribuir-lhes uma das autorias anteriormente aprendidas na referida fase. Caso o documento seja muito dissemelhante de qualquer dos protótipos aprendidos, o sistema deve ser capaz de rejeitar a atribuição de qualquer autoria a este documento. De forma genérica, qualquer problema de classificação parte da assunção de que para objetos diferentes existe algo que os permite distinguir. Assim, uma das grandes dificuldades passa pela identificação de quais atributos presentes nos dados permitem a identificação de cada autor. Após esta fase, um autor será representado pelo conjunto de atributos que o descreve. Assim, idealmente, após esta fase será possível agrupar autores através do grupo escolhido de características (atributos).Document classification is an area with increasing applications. Naturally, the number of studies produced has been increasing and, consequently, the proposals and approaches to the various problems have been improving. The classification of documents is also ramified by the different approaches to each problem, as these approaches differ depend- ing on how the data is presented. The results obtained by each method usually show differences in terms of precision. In general, supervised classification allows obtaining better results when compared to unsupervised classification, where a priori data do not have a known class. In this sense, both the Attribution of Authorship and Plagiarism Verification are part of the document classification. Although with fundamentally different goals, both aim to infer from the data set that make up a document, information about its author. In order to carry out this dissertation, the goal was to develop a system capable of attributing authorship, but also of rejecting a document that is very different from any of the learned prototypes in a training phase. That is, the system receives a set of samples (documents) produced by each author, extracts useful information that represents each one and after being trained, receives new documents and tries to assign them one of the authors previously learned in that phase. If the document is very different from any of the learned prototypes, the system must be able to reject the assignment of any authorship of this document. Generally speaking, any classification problem starts from the assumption that for different objects there is something that allows to distinguish them. So, one of the big difficulties involves the identification of which attributes present in the data allow the identification of each author. After this phase, an author will be represented by the set of attributes that describe it. Thus, ideally, after this phase it will be possible to group authors through the chosen group of characteristics (attributes)