Trains

• James Allen and his group have developed a conversational agent called TRAINS. It's a bit out of date now, yet still shows the state of the art.
• A great deal of effort has gone into the linguistic components.
• The system works with a user to schedule trains, thus the name.
• This requires a complex planning system. A lot of effort was also put into this major component of the system.
• The system works pretty well at performing this collaborative task.
• Note that the task is very domain dependent.
• It's not clear if it was a financially viable system.