ComplexRec 2020

Fourth Workshop on Recommendation in Complex Environments
Co-located with RecSys 2020, Rio de Janeiro

NEWS @ November 20, 2020: The videos of the ComplexRec 2020 talks have now been uploaded to YouTube.

NEWS @ October 12, 2020: The full workshop proceedings are now online at

NEWS @ September 22, 2020: General attendees can join the ComplexRec 2020 session via an embedded Zoom interface on Whova (link to session on Whova). While the proceedings are being prepared, PDF versions of the accepted papers can be found on the Program page.

NEWS @ September 11, 2020: The workshop schedule has been published under ‘Program

NEWS @ August 31, 2020: A list of accepted papers has been published under ‘Program

NEWS @ July 7, 2020: The submission deadline has been extended to July 29th

During the past decade, recommender systems have rapidly become an indispensable element of websites, apps, and other platforms that are looking to provide personalized interaction to their users. As recommendation technologies are applied to an ever-growing array of non-standard problems and scenarios, researchers and practitioners are also increasingly faced with challenges of dealing with greater variety and complexity in the inputs to those recommender systems. For example, there has been more reliance on fine-grained user signals as inputs rather than simple ratings or likes. Many applications also require more complex domain-specific constraints on inputs to the recommender systems. The outputs of recommender systems are also moving towards more complex composite items, such as package or sequence recommendations. This increasing complexity requires smarter recommender algorithms that can deal with this diversity in inputs and outputs.

For the past three years (2017, 2018, 2019), the ComplexRec workshop series has offered an interactive venue for discussing approaches to recommendation in complex scenarios that have no simple one-size-fits-all solution. For the fourth edition of ComplexRec we have narrowed the focus of the workshop and contributions to the workshop about topics related to one of the two main themes on complex recommendation: complex inputs and complex outputs. ComplexRec 2020 will be held on Friday September 25 in the afternoon and will be co-located with RecSys 2020 in Rio de Janeiro, Brazil.

IMPORTANT: ComplexRec 2020 (along with all other RecSys 2020 events) will take place online due to the current Covid-19 pandemic.