Digital Signal Processing Reference
In-Depth Information
Table 3-1 shows the task transition frequencies of Task A and B. The
symbols <d> and </d> indicate the beginning and end of the dialog,
respectively. For instance, the first row of Table 3-l(a) indicates that 148
dialogs of Task A started with an introduction. By following the most
frequent task transitions in Table 3-1 (a), we obtain the task transition <d> -
introduction - traffic - restaurant - tourist attraction - </d>, which suggests
that the typical dialog steps of Task A were: 1) explain to the operator about
the driving plan; 2) ask for traffic information en route to the destination; 3)
ask for restaurant information for lunch; and 4) ask for tourist attraction
information after lunch. On the contrary, the path of the most frequent task
transitions in Table 3-l(b) is <d> - introduction - tourist attraction - </d>,
which does not give us a clear idea of typical dialog steps; this indicates that
the driving plan varies according to the speaker. However, this result
supports the hypothesis that speakers were most interested in tourist
attractions on the second day, as explained above.
The operator sometimes asked the speaker if he/she had any further
questions when the dialog halted. In such cases, the information summarized
in Table 3-1 could be used to suggest a new task to the speaker (to encourage
smooth dialog). For example, the dialog system can suggest the restaurant
task and the traffic task after providing guidance on tourist attractions on the
second day, e.g. “Where would you like to eat lunch?” and “Do you need
traffic information? Traffic congestion is anticipated in the afternoon.”
Figure 3-12.
Average number of utterances per one task.
