Mihaela Cocea Arnon Hershkovitz Ryan Shaun Joazeiro de Baker The Impact of Off-task and Gaming Behaviors on Learning: Immediate or Aggregate? 507-514 2009 AIED http://dx.doi.org/10.3233/978-1-60750-028-5-507 conf/aied/2009 db/conf/aied/aied2009.html#CoceaHB09