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Vita

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Research Interests

  • Opinion dynamics, social influence, group formation
  • Agent-based computer simulations
  • Social network analysis
  • Digital behavioral patterns
  • Dynamics of online tracking data

Selected Contributions

Makhortykh, M., Urman A., & Ulloa, R. (2020). How search engines disseminate information about COVID-19 and why they should do better. Harvard Kennedy School Misinformation Review, 1(3). doi: 10.37016/mr-2020-017

Ulloa, R., and Celina Kacperski. 2020. A Simulation of the Resilience of Cultural Diversity in the Face of Large-Scale Events. http://arxiv.org/abs/2003.05322.

Kacperski, C., Ulloa, R., & Hall, C. (2019). Do Athletes Imagine Being the Best, or Crossing the Finish Line First? A Mixed Methods Analysis of Construal Levels in Elite Athletes’ Spontaneous Imagery. Journal of Mixed Methods Research, 13(2), 216–241. doi: 10.1177/1558689816674563

Ulloa, R. & Froese, T. (2016). Nobility-targeting raids among the Classic Maya: Cooperation in scale-free networks persists under tournament attack when population size fluctuates. Proceedings of the Artificial Life Conference 2016. Cancun, Mexico: MIT press, 472-479. doi:10.7551/978-0-262-33936-0-ch077


Ulloa, R., Kacperski, C., & Sancho, F. (2016). Institutions and cultural diversity: Effects of democratic and propaganda processes on local convergence and global diversity. PLOS ONE, 11(4), 1–26. doi:10.1371/journal.pone.0153334

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Publications

Publikation

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Journal article

Aleksandra, Urman, Mykola Makhortykh, and Roberto Ulloa. 2021. "The matter of chance: auditing web search results related to the 2020 US presidential primary elections across six search engines." Social Science Computer Review online first. https://doi.org/10.1177/08944393211006863.

Makhortykh, Mykola, Aleksandra Urman, and Roberto Ulloa. 2020. "How search engines disseminate information about COVID-19 and why they should do better." The Harvard Kennedy School (HKS) Misinformation Review 1 (Special Issue on COVID-19 and Misinformation): 1-12. doi: http://dx.doi.org/10.37016/mr-2020-017.

Ulloa, Roberto. 2016. "CulSim: A simulator of emergence and resilience of cultural diversity." doi: http://dx.doi.org/10.1016/j.softx.2016.07.005.

Kacperski, Celina, Roberto Ulloa, and Craig Hall. 2016. "Do athletes imagine being the best, or crossing the finish line first? A mixed methods analysis of construal levels in elite athletes’ spontaneous imagery." Journal of Mixed Methods Research 13 (2): 216-241. doi: http://dx.doi.org/10.1177/1558689816674563.

Ulloa, Roberto, Celina Kacperski, and Fernando Sancho-Caparrini. 2016. "Institutions and cultural diversity: Effects of democratic and propaganda processes on local convergence and global diversity." PLoS ONE 11 (4). doi: http://dx.doi.org/10.1371/journal.pone.0153334.

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Contribution to edited volume

Urman, Aleksandra, Mykola Makhortykh, and Roberto Ulloa. 2021. "Auditing source diversity bias in video search results using virtual agents ." In WWW '21: Companion Proceedings of the Web Conference 2021, edited by Jure Leskovec, Marko Grobelnik, Marc Najork, Jie Tang, and Leila Zia, 232–236. New York: ACM. doi: http://dx.doi.org/10.1145/3442442.3452306.

Makhortykh, Mykola, Aleksandra Urman, and Roberto Ulloa. 2021. "Detecting Race and Gender Bias in Visual Representation of AI on Web Search Engines." In Advances in Bias and Fairness in Information Retrieval : Second International Workshop on Algorithmic Bias in Search and Recommendation, BIAS 2021, Lucca, Italy, April 1, 2021, Proceedings, edited by Ludovico Boratto, Stefano Faralli, Mirko Marras, and Giovanni Stilo, Communications in Computer and Information Science 1418, 36-50. Springer, Cham. doi: http://dx.doi.org/10.1007/978-3-030-78818-6_5.

Ulloa, Roberto, and Tom Froese. 2016. "Nobility-targeting raids among the Classic Maya: Cooperation in scale-free networks persists under tournament attack when population size fluctuates." In Proceedings of the Artificial Life Conference 2016, 472-479. MIT Press. doi: http://dx.doi.org/10.7551/978-0-262-33936-0-ch077.

Ulloa, Roberto, and Gabriela Barrantes. 2012. "Snapshot of the position of a site in the Internet: Vector space model applied to external pages." In Proceedings of the XXXVIII Latin American Informatics Conference, IEEE. doi: http://dx.doi.org/10.1109/CLEI.2012.6427223.

Ulloa, Roberto. 2009. "Parallel opponent modelling with knowledge domain: Direct search of strategies in multi-agent systems." In Proceedings of the XXXV Latin American Informatics Conference, CLEI. doi: http://dx.doi.org/10.13140/RG.2.1.2688.2803.

Ulloa, Roberto, and Gabriela Barrantes. 2008. "Building a scenario for the simulation of attacks on systems of agents." SCCC. In Jornadas Chilenas de Computación, doi: http://dx.doi.org/10.13140/RG.2.1.4785.4324.

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Monograph

Ulloa, Roberto. 2016. Cultural Diversity in Artificial Societies: Case Studies of the Maya Peoples. Electronic Thesis and Dissertation Repository. The University of Western Ontario. https://ir.lib.uwo.ca/etd/4231 .

Ulloa, Roberto. 2015. Kivy: Interactive Applications and Games in Python. 2. Packt Publishing.

Ulloa, Roberto. 2013. Kivy: Interactive Applications in Python . 1. Packt Publishing.

Ulloa, Roberto. 2011. Uso de aleatorización como un mecanismo de defensa frente a la inferencia de estrategias en sistemas multiagente. MSc Dissertation. Universidad de Costa Rica. Sistema de Estudios de Posgrado. http://repositorio.sibdi.ucr.ac.cr:8080/jspui/handle/123456789/2545.

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Working and discussion paper

Ulloa, Roberto, Mykola Makhortykh, and Aleksandra Urman. 2021. Algorithm Auditing at a Large-Scale: Insights from Search Engine Audits. Arxiv. https://arxiv.org/abs/2106.05831.

Ulloa, Roberto, and Celina Kacperski. 2020. A simulation of the resilience of cultural diversity in the face of large-scale events. ArXiV Preprint. http://arxiv.org/abs/2003.05322.

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Variable Report

2012. Recognition between Baroque and Renaissance Style of Classic Paintings. doi: http://dx.doi.org/10.13140/RG.2.1.3154.9203.

Talk

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Conference contribution

Urman, Aleksandra, Mykola Makhortykh, and Roberto Ulloa. 2021. "Auditing source diversity bias in video search results using virtual agents ." 3rd International Workshop on Algorithmic Bias in Search and Recommendation (FATES 2021), 12.04.2021.

Urman, Aleksandra, Mykola Makhortykh, and Roberto Ulloa. 2021. "Detecting race and gender bias in visual representation of AI on web search engines." 2nd International Workshop on Algorithmic Bias in Search and Recommendation (BIAS 2021), 01.04.2021. doi: http://dx.doi.org/10.1177/08944393211006863.

Ulloa, Roberto. 2021. "Hey, Google, tell me what the Holocaust looked like: Visual framing of mass atrocities by search engines." Three-Country Conference on Communication Science (DACH 21), Universität Zürich, 08.04.2021.

Makhortykh, Mykola, Aleksandra Urman, and Roberto Ulloa. 2021. "Scaling virtual agent-based testing for cross-platform analysis of algorithmic content curation." Three-Country Conference on Communication Science (DACH 21), Universität Zürich, 07.04.2021.

Urman, Aleksandra, Mykola Makhortykh, and Roberto Ulloa. 2020. "Poster on Auditing search engines: The case of the 2020 US presidential election campaign." Virtuell: Socinfo 2020, 06.10.2020.

Makhortykh, Mykola, Aleksandra Urman, and Roberto Ulloa. 2020. "This is what pandemic looks like: Visual framing of COVID-19 on search engines." 14th General Conference (ECPR 2020), 24.08.2020.

Ulloa, Roberto. 2020. "To track or not to track: Examining perceptions of online tracking in the context of information behaviour research." Online: 70th Annual ICA Conference, Open Communication, 21.05.2020.

Urman, Aleksandra, Mykola Makhortykh, Teresa Gil-Lopez, and Roberto Ulloa. 2020. "Would you kindly let us track you?: Examining perceptions of online tracking in the context of information behaviour research." 9th biennial Surveillance & Society conference of the Surveillance Studies Network, Erasmus University Rotterdam, Rotterdam, Netherlands, 07.06.2020.

Ulloa, Roberto. 2016. "Nobility-targeting raids among the Classic Maya: Cooperation in scale-free networks persists under tournament attack when population size fluctuates." Poster on XV Conference on the Synthesis and Simulation of Living Systems.

Kacperski, Celina, Roberto Ulloa, and Craig Hall. 2014. "A qualitative analysis of construal levels in sport imagery." ASP - Performing under Pressure.

Suárez, Juan Luis, Javier de la Rosa, and Roberto Ulloa. 2013. "Poster on Not Exactly Prima Facie: Understanding the Representation of the Human Through the Analysis of Faces in World Painting." Digital Humanities 2013 Conference.

Ulloa, Roberto. 2012. "Snapshot of the position of a site in the Internet: Vector space model applied to external pages." XXXVIII Latin American Informatics Conference, 05.03.2013.

Ulloa, Roberto. 2009. "Parallel opponent modelling with knowledge domain: Direct search of strategies in multiagent systems." XXXV Latin American Informatics Conference.

Ulloa, Roberto. 2008. "Building a scenario for the simulation of attacks on systems of agents." Jornadas Chilenas de Computación. doi: http://dx.doi.org/10.13140/RG.2.1.4785.4324.

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Contribution not at conference

Ulloa, Roberto. 2016. "CulSim: Emergence and Resilience of Cultural Diversity in a Computer Simulator." Poster on 3rd GESIS Computational Social Science Winter Symposium.

Other

Flöck, Fabian, Kenan Erdogan, Roberto Ulloa, and Maribel Acosta. 2015. "WikiWho Web Service : Extraction of Wikipedia Editor Interactions and Change Tracking."