dr. ir.Bozdag, E. (Engin)

Delft University of Technology

Section: Values, Technology and Innovation
Faculty: Technology, Policy and Management

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Engin’s PhD project focused on bias in big-data algorithms, algorithmic transparency and the phenomenon “filter bubble”‚Äč. Many scholars claimed that social media tools such as Google and Facebook have opaque filtering algorithms that personalize information on user’s behalf without their consent. Such opaque algorithms are trying to improve accuracy at the expense of diversity and has a negative effect on users’ autonomy. As a result, users never see the other side of an argument, get trapped in their ideological bubbles, and civic discourse is undermined. Engin’s thesis first analyzes internal processes and factors in online web services that might cause filter bubbles. Later, it presents the results of an empirical study for Dutch and Turkish Twitter users. The thesis also analyzes software tools and design attempts to combat filter bubbles. It demonstrates that almost all of the tools implement norms required by two popular democracy models. The thesis argues that democracy is essentially a contested concept, and that other less popular democracy models should be included in the design of such tools as well.

Currently, Engin works as Privacy by Design lead at Philips and previously worked for Google and PwC Netherlands. He was the winner of NWO’s Mozaiek 2010 grant. Engin completed both his MSc and BSc degrees in Computer Science, specializing in web based applications (Delft, 2008).

Scientific publications (selection)


  • Bozdag E. and van den Hoven J. 2015. Bursting the Filter Bubble: Democracy and Design. Ethics and Information Technology (forthcoming)


  • Bozdag E., Gao Q., Houben G.J., Warnier M. Does Offline Political Segregation Affect the Filter Bubble? An Empirical Analysis of Information Diversity for Dutch and Turkish Twitter Users. Computers in Human Behavior, Elsevier ScienceDirect (2014) available online
  • Puschmann C. and Bozdag E. 2014. Staking out the unclear ethical terrain of online social experiments. Internet Policy Review. Volume 3, Issue 4. Published on 26 Nov 2014. 10.14763/2014.4.338 click to open pdf


  • Bozdag E. and Gao Q. An empirical research design for analyzing information diversity in Twitter for Dutch and Turkish users. In proceedings of ETHICOMP 2013, University of Southern Denmark, Kolding, Denmark, 2013.
  • Bozdag E. and van de Poel I. Designing for diversity in online personalization systems. In proceedings of Technology Management for Emerging Technologies Conference (PICMET), San Jose, USA, 2013.
  • Bozdag E. Bias in Algorithmic Filtering and Personalization. Ethics and Information Technology. forthcoming.
  • Bozdag E., Gao Q., Warnier M. and Houben G. Analyzing viewpoint diversity in Twitter. Proceedings of "Designing Social Media for Change" Workshop, The ACM SIGCHI Conference on Human Factors in Computing Systems (CHI). Paris, 2013.
  • Bozdag, Engin. 2013. Bias in Algorithmic Filtering and Personalization. In Ethics and Information Technology. September 2013, Volume 15, Issue 3, pp 209-227


  • Bozdag, E., and Timmermans, J. 2011. "Values in the Filter Bubble: Ethics of Personalization Algorithms in Cloud Computing". In Proceedings of the 13th IFIP TC13 Conference on Human-Computer Interaction (Interact), Workshop on Values in Design - Building Bridges between HCI, RE and Ethics, Lisbon, Portugal.


  • Timmermans, J., Stahl, B.C., Ikonen V., and Bozdag, E., 2010. "The Ethics of Cloud Computing: A Conceptual Review". Cloud Computing, HCI, & Design: Sustainability and Social Impacts, 2nd IEEE International Conference on Cloud Computing Technology and Science (CloudCom 2010), Indianapolis, USA.


  • Engin Bozdag, Ali Mesbah, and Arie van Deursen. Performance testing of data delivery techniques for AJAX applications. In Journal of Web Engineering (JWE), volume 8, pages 287. 315, 2009.


  • Ali Mesbah, Engin Bozdag, and Arie van Deursen. Crawling AJAX by inferring user interface state changes. In 8th International Conference on Web Engineering (ICWE08), 2008.
  • Engin Bozdag and Arie van Deursen. An adaptive push/pull algorithm for AJAX applications. In Third International Workshop on Adaptation and Evolution in Web Systems Engineering (AEWSE 08), July 2008.


  • Engin Bozdag, Ali Mesbah, and Arie van Deursen. A comparison of push and pull techniques for AJAX. In Proceedings of the 9th IEEE International Symposium on Web Site Evolution (WSE), pages 15- 22. IEEE Computer Society, 2007

Professional/Popular publications (selection)


  • Engin Bozdag and Martijn Warnier. Sociale media over protesten in Istanbul: democratiserend of juist polariserend? Volkskrant, 29.06.2013 available online
  • Engin Bozdag en Martijn Warnier. Polarisatie door sociale media Turkije. NRC Handelsblad, 1 Juli 2013 click to open pdf


Engin Bozdag on the role of the social media in Turkey

July 4, 2013 — 3TU-member Engin Bozdag recently published two opinion articles in the Dutch news papers NRC and Volkskrant Online on the role [more...]