@inproceedings{venetis2011selection,
  abstract = {We examine the creation of a tag cloud for exploring and understanding a set of objects (e.g., web pages, documents). In the first part of our work, we present a formal system model for reasoning about tag clouds. We then present metrics that capture the structural properties of a tag cloud, and we briefly present a set of tag selection algorithms that are used in current sites (e.g., del.icio.us, Flickr, Technorati) or that have been described in recent work. In order to evaluate the results of these algorithms, we devise a novel synthetic user model. This user model is specifically tailored for tag cloud evaluation and assumes an "ideal" user. We evaluate the algorithms under this user model, as well as the model itself, using two datasets: CourseRank (a Stanford social tool containing information about courses) and del.icio.us (a social bookmarking site). The results yield insights as to when and why certain selection schemes work best.},
  acmid = {1935855},
  address = {New York, NY, USA},
  author = {Venetis, Petros and Koutrika, Georgia and Garcia-Molina, Hector},
  booktitle = {Proceedings of the fourth ACM international conference on Web search and data mining},
  doi = {10.1145/1935826.1935855},
  interhash = {fc7ea4080c46677eeda3a69b67e89d77},
  intrahash = {c3ccbbcd57d5c65a03f6f4e8b1eccd02},
  isbn = {978-1-4503-0493-1},
  location = {Hong Kong, China},
  numpages = {10},
  pages = {835--844},
  publisher = {ACM},
  series = {WSDM '11},
  title = {On the selection of tags for tag clouds},
  url = {http://doi.acm.org/10.1145/1935826.1935855},
  year = 2011
}

@inproceedings{bercovitz2009courserank,
  abstract = {Special-purpose social sites can offer valuable services to well-defined, closed, communities, e.g., in a university or in a corporation. The purpose of this demo is to show the challenges, special features and potential of a focused social system in action through CourseRank, a course evaluation and planning social system.},
  address = {New York, NY, USA},
  author = {Bercovitz, Benjamin and Kaliszan, Filip and Koutrika, Georgia and Liou, Henry and Zadeh, Zahra Mohammadi and Garcia-Molina, Hector},
  booktitle = {SIGMOD '09: Proceedings of the 35th SIGMOD International Conference on Management of Data},
  doi = {10.1145/1559845.1559994},
  interhash = {7b8dc7f8afc7c0f6335a7ca2767f6c4e},
  intrahash = {ea4b746455b0b26bdf5fcfd090b63afb},
  isbn = {978-1-60558-551-2},
  location = {Providence, Rhode Island, USA},
  pages = {1107--1110},
  publisher = {ACM},
  title = {CourseRank: a social system for course planning},
  url = {http://portal.acm.org/citation.cfm?id=1559845.1559994},
  year = 2009
}

@inproceedings{koutrika2009flexible,
  abstract = {Most recommendation methods are "hard-wired" into the system and support only fixed recommendations. The purpose of this demo is to show the expressivity of flexible recommendation workflows, how flexible recommendations can be processed over relational data, and to show flexible recommendations in action through a real system used for course planning.},
  address = {Washington, DC, USA},
  author = {Koutrika, Georgia and Bercovitz, Benjamin and Ikeda, Robert and Kaliszan, Filip and Liou, Henry and Garcia-Molina, Hector},
  booktitle = {ICDE '09: Proceedings of the 2009 IEEE International Conference on Data Engineering},
  doi = {10.1109/ICDE.2009.127},
  interhash = {f6c15a42f29b91878d66a5b8509e8cee},
  intrahash = {ce4698c62c28047b05dde13c68ef1b50},
  isbn = {978-0-7695-3545-6},
  pages = {1467--1470},
  publisher = {IEEE Computer Society},
  title = {Flexible Recommendations for Course Planning},
  url = {http://portal.acm.org/citation.cfm?id=1547343},
  year = 2009
}

@article{koutrika2009social,
  abstract = {Social sites have become extremely popular among users but have they attracted equal attention from the research community? Are they good only for simple tasks, such as tagging and poking friends? Do they present any new or interesting research challenges? In this paper, we describe the insights we have obtained implementing CourseRank, a course evaluation and planning social system. We argue that more attention should be given to social sites like ours and that there are many challenges (though not the traditional DBMS ones) that should be addressed by our community. },
  author = {Koutrika, Georgia and Bercovitz, Benjamin and Ikeda, Robert and Kaliszan, Filip and Liou, Henry and Zadeh, Zahra Mohammadi and Garcia-Molina, Hector},
  date = {2009-10-02},
  interhash = {19eb6f3c278a1a65ac18d38dadf3c71d},
  intrahash = {265a2c4624b42bf309858d1039c39c4d},
  journal = {CoRR},
  month = oct,
  note = {informal publication},
  title = {Social Systems: Can we Do More Than Just Poke Friends?},
  url = {http://arxiv.org/abs/0909.1774},
  volume = {abs/0909.1774},
  year = 2009
}

@article{journals/internet/HeymannKG07,
  author = {Heymann, Paul and Koutrika, Georgia and Garcia-Molina, Hector},
  date = {2007-11-08},
  ee = {http://doi.ieeecomputersociety.org/10.1109/MIC.2007.125},
  interhash = {dea5faea536678622993617bfc5fbb85},
  intrahash = {8a293527604e19085173fa461340f55e},
  journal = {IEEE Internet Computing},
  number = 6,
  pages = {36-45},
  title = {Fighting Spam on Social Web Sites: A Survey of Approaches and Future Challenges.},
  url = {http://dblp.uni-trier.de/db/journals/internet/internet11.html#HeymannKG07},
  volume = 11,
  year = 2007
}

@inproceedings{koutrika2007combating,
  address = {New York, NY, USA},
  author = {Koutrika, Georgia and Effendi, Frans Adjie and Gy\"{o}ngyi, Zolt\'{a}n and Heymann, Paul and Garcia-Molina, Hector},
  booktitle = {AIRWeb '07: Proceedings of the 3rd international workshop on Adversarial information retrieval on the web},
  doi = {http://doi.acm.org/10.1145/1244408.1244420},
  interhash = {8b6de1f035a46f5465f1ed868a18c79a},
  intrahash = {776b76b33d469e438b0e5f74fc7ec7f0},
  isbn = {978-1-59593-732-2},
  location = {Banff, Alberta, Canada},
  pages = {57--64},
  publisher = {ACM Press},
  title = {Combating spam in tagging systems},
  url = {http://portal.acm.org/citation.cfm?id=1244408.1244420},
  year = 2007
}

@inproceedings{heyman2008social,
  abstract = {Social bookmarking is a recent phenomenon which has the potential to give us a great deal of data about pages on the web. One major question is whether that data can be used to augment systems like web search. To answer this question, over the past year we have gathered what we believe to be the largest dataset from a social bookmarking site yet analyzed by academic researchers. Our dataset represents about forty million bookmarks from the social bookmarking site del.icio.us. We contribute a characterization of posts to del.icio. us: how many bookmarks exist (about 115 million), how fast is it growing, and how active are the URLs being posted about (quite active). We also contribute a characterization of tags used by bookmarkers. We found that certain tags tend to gravitate towards certain domains, and vice versa. We also found that tags occur in over 50 percent of the pages that they annotate, and in only 20 percent of cases do they not occur in the page text, backlink page text, or forward link page text of the pages they annotate. We conclude that social bookmarking can provide search data not currently provided by other sources, though it may currently lack the size and distribution of tags necessary to make a significant impact},
  address = {New York, NY, USA},
  author = {Heymann, Paul and Koutrika, Georgia and Garcia-Molina, Hector},
  booktitle = {WSDM '08: Proceedings of the International Conference on Web Search and Web Data Mining},
  doi = {10.1145/1341531.1341558},
  interhash = {3192b26a3b1394e24283766de46dc14b},
  intrahash = {f322b6ec3e4aee71bd7ff9798f70a96e},
  isbn = {978-1-59593-927-9},
  location = {Palo Alto, California, USA},
  pages = {195--206},
  publisher = {ACM},
  title = {Can social bookmarking improve web search?},
  url = {http://doi.acm.org/10.1145/1341531.1341558},
  year = 2008
}

@inproceedings{Koutrika2007,
  author = {Koutrika, Georgia and Effendi, Frans Adjie and Gy\"{o}ngyi, Zolt\'{a}n and Heymann, Paul and Garcia-Molina, Hector},
  booktitle = {AIRWeb '07: Proc. of the 3rd int. workshop on Adversarial inf. retrieval on the web},
  interhash = {8b6de1f035a46f5465f1ed868a18c79a},
  intrahash = {899758f0e2b090bd3d6c24093ff7b94e},
  pages = {57--64},
  title = {Combating spam in tagging systems},
  year = 2007
}

@inproceedings{koutrika2009flexrecs,
  abstract = {Recommendation systems have become very popular but most recommendation methods are ‘hard-wired’ into the system making experimentation with and implementation of new recommendation paradigms cumbersome. In this paper, we propose  FlexRecs, a framework that decouples the definition of a recommendation process
from its execution and supports flexible recommendations over structured data. In FlexRecs, a recommendation approach can be
defined declaratively as a high-level parameterized workflow comprising
traditional relational operators and new operators that generate or combine recommendations. We describe a prototype flexible recommendation engine that realizes the proposed framework and we present example workflows and  experimental results that show its potential for capturing multiple, existing or novel, recommendations
easily and having a flexible recommendation system that combines extensibility with reasonable performance.},
  author = {Koutrika, Georgia and Bercovitz, Benjamin and Garcia-Molina, Hector},
  booktitle = {SIGMOD 2009},
  interhash = {f01092f743380c0566fe6053c3547727},
  intrahash = {78b4039402063466897dd154e58b73ca},
  publisher = {Stanford InfoLab},
  title = {FlexRecs: Expressing and Combining Flexible Recommendations},
  url = {http://ilpubs.stanford.edu:8090/907/},
  year = 2009
}

@inproceedings{Heymann2008,
  address = {New York, NY, USA},
  author = {Heymann, Paul and Koutrika, Georgia and Garcia-Molina, Hector},
  booktitle = {WSDM '08: Proceedings of the international conference on Web search and web data mining},
  interhash = {3192b26a3b1394e24283766de46dc14b},
  intrahash = {7ffee89349e08beef1b55ab9d68ddd30},
  pages = {195--206},
  publisher = {ACM},
  title = {Can social bookmarking improve web search?},
  year = 2008
}