Generation Challenges 2011 Preface.

Generation Challenges 2011 (GenChal'11) was the fifth round of shared-task evaluation competitions (STECs) involving the generation of natural language. It followed four previous events: the Pilot Attribute Selection for Generating Referring Expressions (ASGRE) Challenge in 2007 which had its results meeting at UCNLG+MT in Copenhagen, Denmark; Referring Expression Generation (REG) Challenges in 2008, with a results meeting at INLG'08 in Ohio, US; Generation Challenges 2009 with a results meeting at ENLG'09 in Athens, Greece; and most recently Generation Challenges 2010 with a results meeting at INLG'10 in Trim, Ireland. More information about all these NLG STEC events can be found via the links on the Generation Challenges homepage (http://www.nltg.brighton.ac.uk/research/genchal11).