In order to be able to develop and test techniques in improving spoken dialog systems, a baseline system was built. CMU has significant experience in building spoken dialog systems. Since we want to have significant control of the dialog system, completely off-the-shelf systems supporting VoiceXML-like directed dialog would be too restrictive. We therefore chose to build on the RavenClaw  system. This system is in turn built upon the MIT Galaxy architecture  and uses the CMU Sphinx speech recognizer  and the Festival Speech Synthesis System .