A belief tracking challenge task for spoken dialog systems Jason Williams author 2012-06 text NAACL-HLT Workshop on Future directions and needs in the Spoken Dialog Community: Tools and Data (SDCTD 2012) Maxine Eskenazi editor Alan Black editor David Traum editor Association for Computational Linguistics Montréal, Canada conference publication williams-2012-belief https://aclanthology.org/W12-1812/ 2012-06 23 24