Dialog System - Components

Components

There are many different architectures for dialog systems. What sets of components are included in a dialog system, and how those components divide up responsibilities differs from system to system. Principal to any dialog system is the dialog manager, which is a component that manages the state of the dialog, and dialog strategy. A typical activity cycle in a dialog system contains the following phases:

1. The user speaks, and the input is converted to plain text by the system's input recognizer/decoder, which may include:
   • automatic speech recognizer (ASR)
   • gesture recognizer
   • handwriting recognizer
2. The text is analyzed by a Natural language understanding unit (NLU), which may include:
   • Proper Name identification
   • part of speech tagging
   • Syntactic/semantic parser
3. The semantic information is analyzed by the dialog manager, that keeps the history and state of the dialog and manages the general flow of the conversation.
4. Usually, the dialog manager contacts one or more task managers, that have knowledge of the specific task domain.
5. The dialog manager produces output using an output generator, which may include:
   • natural language generator
   • gesture generator
   • layout engine
6. Finally, the output is rendered using an output renderer, which may include:
   • text-to-speech engine (TTS)
   • talking head
   • robot or avatar

Dialog systems that are based on a text-only interface (e.g. text-based chat) contain only stages 2-5.