This article provides a global overview of the main aspects of current practice in the design,
implementation and evaluation of speech recognition components for Spoken Language
Dialog Systems (SLDSs), and presents the results of the DISC European project related
to speech recognition. DISC and its successor DISC-2 are efforts towards the definition of
best practice guidelines for SLDS development and evaluation. SLDSs aim at using natural
spoken input for performing an information processing task such as automated standards,
call routing or travel planning and reservations. The main functionality of an SLDS are
speech recognition, natural language understanding, dialog management, database access and
interpretation, response generation and speech synthesis. Speech recognition, which transforms
the acoustic signal into a string of words, is a key technology in any SLDS.