NLU vs. Directed Dialog

Explanation of directed dialog.

In a directed dialog, the caller is lead by the IVR step-by-step through the transaction. Each individual piece of information is handled in a separate dialog state. So taking the infamous flight booking example:

Where would you like to fly to?

Rome

On what date would you like to leave?

Tomorrow

Around what time would you like to depart?

10 am

Provided the recognition rates are high enough for each question, there is little need to confirm every input. However, the details have to be confirmed at some point:

So you would like to fly to Rome tomorrow morning at 10 am. Is that correct?

Yes

Explanation of NLU

NLU stands for Natural Language Understanding. This is a grandiose way of saying that the recogniser can handle sentences rather than pure command and control words. Sentences allow the caller to provide more information in one go, than is possible with directed dialogs. This is advantageous in the sense that it let’s the customer feel more in charge and less stuck in a loop with a machine:

Where would you like to fly to?

I need to fly to Rome tomorrow morning at about 10 am.

Let me check - you would like to fly to Rome tomorrow morning at 10 am. Is that correct?

Yes

However, if NLU doesn’t work, then you are reduced to a directed dialog anyway:

Where would you like to fly to?

I need to fly to Rome tomorrow morning at about 10 am.

Ok - you would like to fly to Rome this morning at 10 am. Is that correct?

No!

Now you have to find out what was wrong with the recogniser's result. In theory, with NLU the caller should be able to provide the correct information in his reply:

No! I want to fly tomorrow morning, not this morning!

However, that's one tricky grammar to create, so you may be reduced to a directed dialog:

Where would you like to fly to?

I need to fly to Rome tomorrow morning at about 10 am.

Ok - you would like to fly to Rome this morning at 10 am. Is that correct?

No!

What did I get wrong? The destination, the date or the time?

The date

On what date would you like to leave?

Tomorrow

Let me check - you would like to fly to Rome tomorrow morning at 10 am. Is that correct?

Yes

And the question is, if the customer hasn’t had too much experience of bad IVRs, does a directed dialog really bother them?

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