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1. the dialogue manager (DM) takes care of updating a set of special variables (e.g. the time since the last user action). These special variables can be found in a file called specialVariables.xml in the dm sub-directory. The file is automatically generated every time the DM starts.
2. event listeners: one can associate to certain events automatic updates that are executes every time a particular event is received. these updates are also called state less updates because they happen regardless of the current action or best selected action.
3. effects: as described in the Authoring for the FLoReS NL module section above, a sub-dialogue node can have a specific effect to update the value of a certain variable.
4. forward inference rules: one can specify an ordered list of implications. They are executed every time a change is made to the information state. when one is found in which the antecedent of the implication is true, the consequent is executed. For example, give the rule "if A then B else C" if A is true, then B is executed otherwise C is executed. The else part is optional. A is a Boolean expression. B and C are assignments.

Special variables:

The dialogue manager has a predefined set of special variables it updates automatically and that can be used in a dialogue policy, if needed.

This list of special variable can vary with each version of the dialogue manager. The list is printed out in a file called specialVariables.xml in the dm sub-directory. The content is for example:

<sv id="timeSinceLastUserAction" value="0" type="NUMBER" desc="Time in seconds since the last thing said by the user."/>
<sv id="timeSinceLastSystemAction" value="0" type="NUMBER" desc="Time in seconds since the last thing said by the system."/>
<sv id="consecutiveUnhandledUserActions" value="0" type="NUMBER" desc="Number of consecutive user actions for which the system had no direct response (handler)."/>
<sv id="timeSinceLastAction" value="0" type="NUMBER" desc="Time in seconds since anyone said something (user or system)."/>
<sv id="timeSinceLastResource" value="0" type="NUMBER" desc="Time in seconds since the last resource link/video was given."/>
<sv id="event" value="null" type="TEXT" desc="Name of last speech act said by the user and processed by the system."/>
<sv id="lastNonNullSubdialog" value="null" type="TEXT" desc="Name of last sub-dialog executed by the system."/>
<sv id="systemEvent" value="null" type="TEXT" desc="Name of the speech act last said by the system."/>
<sv id="timerInterval" value="1" type="NUMBER" desc="Time in seconds between 2 consecutive timer events."/>
<sv id="preferForms" value="true" type="BOOLEAN" desc="If true and a form is available for the current system speech act, the form will be selected by the NLG."/>

Each line found in that file shows a special variable. id is the name of the variable to be used if you want to refer to that variable in your dialogue policies. value is the initial value given to that variable at start-up. type specifies the type of the variable (just to give you an idea, variables are untyped so you can change if want what that variable stores, but when the dialogue manager will automatically update that variable it'll write again something that belongs to the predefined type found in this description). desc contains a textual description of what that variable contains.

Dialogue policy execution

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