Successful 2nd International Alexandria Workshop

IMG_0833_smThe second Alexandria Workshop took place in L3S Research Center on 2-3rd November 2015. The workshop was aimed at bringing together communities involved in web archiving, digital preservation, digital humanities and information retrieval to encourage a closer dialogue between researchers from computer science, digital humanities and cultural heritage institutions. It was widely attended from participants from national libraries, humanities to computer scientists from varying disciplines like Information retrieval, natural language processing, database systems and distributed systems. The workshop, spanning two days, included two keynotes, several research talks, system demonstrations and a panel discussion on shortcomings, research infrastructures, and future directions.

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2nd International Alexandria Workshop

Alexandria LogoFoundations for Temporal Retrieval, Exploration and Analytics in Web Archives

2./3. November 2015

L3S Research Center, Hannover, Germany

Significant parts of our cultural heritage are produced on the Web, yet only insufficient opportunities exist for accessing and exploring the past of the Web. While the easy accessibility to the current Web is a good baseline, optimal access to Web archives requires new models and algorithms for retrieval, exploration, and analytics which go far beyond what is needed to access the current state of the Web. This includes taking into account the unique temporal dimension of Web archives, structured semantic information already available on the Web, as well as social media and network information.

The workshop aims at bringing together communities involved in Web Archiving, Digital Preservation, Digital Humanities and Information Retrieval to encourage a closer dialogue between researchers from computer science, digital humanities and cultural heritage institutions.

Click here for more detailed information, agenda, venue, etc.

Alexandria @ WWW 2015

The ALEXANDRIA logo_crproject team participated in the 14th International Conference on World Wide Web (WWW ’15) in Florence, Italy in May 2015. We contribute one full paper for the main conference and two full papers for the workshops.


Contribution to the main conference:

Markus Rokicki, Sergej Zerr, Stefan Siersdorfer. “Groupsourcing: Team Competition Designs for Crowdsourcing”

Many data processing tasks such as semantic annotation of images, translation of texts in foreign languages, and labeling of training data for machine learning models require human input, and, on a large scale, can only be accurately solved using crowd based online work. Recent work shows that frameworks where crowd workers compete against each other can drastically reduce crowdsourcing costs, and outperform conventional reward schemes where the payment of online workers is proportional to the number of accomplished tasks (“pay-per-task”). In this paper, we investigate how team mechanisms can be leveraged to further improve the cost efficiency of crowdsourcing competitions. To this end, we introduce strategies for team based crowdsourcing, ranging from team formation processes where workers are randomly assigned to competing teams, over strategies involving self-organization where workers actively participate in team building, to combinations of team and individual competitions. Our large-scale experimental evaluation with more than 1,100 participants and overall 5,400 hours of work spent by crowd workers demonstrates that our team based crowdsourcing mechanisms are well accepted by online workers and lead to substantial performance boosts.


Markus Rokicki during his presentation

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Successful 1st International Alexandria Workshop

On September 15th/16th the 1st International Alexandria Workshop took place at the L3S Research Center. The attractive program attracted around 50 researchers and practitioners involved in Web Archiving, Digital Preservation, Digital Humanities and Information Retrieval from all over the world to get insights in the newest developments and trends in using and analyzing Web archives.


Wolfgang Nejdl about the Alexandria Project

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Alexandria @ SIGIR 2014

sigir2014The ALEXANDRIA project team participated in the 37th Annual ACM SIGIR Conference (SIGIR’2014) in Gold Coast, Australia in July 2014. We contribute in one full paper and two short papers for the main conference, two full papers for the workshops, and a demo paper. The list of our publications at SIGIR’2014 are as follows:




Full paper

  • Xiaofei Zhu, Wolfgang Nejdl and Mihai Georgescu. “An Adaptive Teleportation Random Walk Model for Learning Social Tag Relevance”

Social tags are known to be a valuable source of information for image retrieval and organization. However, contrary to the conventional document retrieval, rich tag frequency information in social sharing systems, such as Flickr, is not available, thus we cannot directly use the tag frequency (analogous to the term frequency in a document) to represent the relevance of tags. Many heuristic approaches have been proposed to address this problem, among which the well-known neighbor voting based approaches are the most effective methods. The basic assumption of these methods is that a tag is considered as relevant to Read the rest of this entry »

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