The language of the dialogues is American-English.
Relevance is defined in terms of necessity to the continuation of the task defined in the dialogue.
A decision procedure concerning how to carve segments out of dialogues is specified, together with 'rules of the thumb' regarding possible correspondences between surface forms and segments boundaries. Discourse phenomena such as greetings, introductions, offers to help, back-channel phenomena, prompts for continuation, thanks and closings are not recognized as having a relevant status for segmentation. Only segments directly dealing with task-relevant information are signaled and annotated. N.b.'s mark-up language. This is not fully compliant with SGML, but a program is distributed with Nb that converts Nb-annotated files into standard SGML files.