
## - Acoustic/Asr Features

recog  recog numwords  asr duration  dtmf flag  rg modality  rg grammar  tempo

## - Slu Features

tin a confidence measure for each of the possible tasks that the user could be trying to do sssence coverage inconsistency context shift top task nexttop task of top confidence diff confidence confpertime salpertime auto SLU success

## - Dialogue Manager And Discourse History Features

sys label utt id prompt reprompt confirmation subdial running tallies num utts num reprompts percent reprompts num confirms percent confirms  num subdials  percent subdials whole dialogue  dial duration

## - Hand-Labelled Features

tscript   human label   age   gender  
user modality   clean tscript cltscript numwords  SLU success Features for spoken dialogues Figure A dialogue consists of a sequence of exchanges where each exchange consists of one turn by the system followed by one turn by the user  Ea dialogue and exange is encoded using the set of    features in Figure    Each feature was either automatically logged by one of the system modules  hand labelled by humans  or derived from raw features   The hand labelled features are used to produce a topline an estimation of how well a classifier could do that had access to perfect information  To see whether our results can generalize we also experiment with using a subset of features that are task independent described in detail below Features logged by the system are utilized because they are produced automatically and thus can be used during runtime to alter the course of the dialogue  The system modules for which logging information was collected were the acoustic processor  automatic the spoken language understanding   SLU
speech recognizer  ASR   Riccardi    Gorin   
module   Gorin et al and the Dialogue Manager  DM   Abella    Gorin Each module and the features obtained from it are described below Automatic Speech Recognition The automatic spee recognizer  ASR  takes as input the callers spee and produces a potentially errorful transcription of what it be leves the caller said The ASR features for each exchange include the output of the speech recognizer  recog  the number of words in the recognizer output  recog-numwords the duration in seconds of the input to the recognizer asr-duration a flag for touchtone in