21. The dialog system of claim 1 , wherein: the nodes are hierarchically organized in the dialog move tree, and for each of at least a subset of the nodes of the dialog move tree, dialog manager determines to which of plurality of dialog moves represented by nodes previously added to the dialog move tree the respective node relates, and adds the respective node as a child of the determined node.
21. The dialog system of claim 1 , wherein: the nodes are hierarchically organized in the dialog move tree, and for each of at least a subset of the nodes of the dialog move tree, dialog manager determines to which of plurality of dialog moves represented by nodes previously added to the dialog move tree the respective node relates, and adds the respective node as a child of the determined node. 23. The dialog system of claim 21 , wherein the dialog manager determines that a node is related as a child to another node by determining that a dialog move to which the node corresponds is provided as a response to a dialog move to which the another node corresponds.