NLU is not a User Interface

Some time ago I already spoke about NLU vs Dialogmanagement. My hope was that people working in NLU and Voice User Interface design would start talking to each other. I enhanced these ideas in a paper submitted to the IUI Workshop on Interacting with Smart Objects: NLU vs. Dialog Management: To Whom am I Speaking? In essence "Dialogmangement-centered  systems  are  principally  constrained  because they anticipate the users input as plans to help them to achieve their goal.   Depending  on  the  implemented  dialog  strategy they allow for different degrees of flexibility. NLU-centered systems see the central point in the semantics of the utterance, which should also be grounded with previous utterances or external content.  Thus, whether speech or not, NLU regards this as a stream of some input to produce some output. Since no dialog model is employed,  resulting user interfaces currently do not handle much more than single queries".

Actual dialog systems must go beyond this and combine knowledge from both research domains to provide convincing user interfaces.

Now, I stumbled across a blog entry from Matthew Honnibal who bemoans the current hype around artificial intelligence and the ubiquitous promise for more natural user interfaces. He is right that voice simply is another user interface. He states:  "My point here is that a linguistic user interface (LUI) is just an interface. Your application still needs a conceptual model, and you definitely still need to communicate that conceptual model to your users. So, ask yourself: if this application had a GUI, what would that GUI look like?"

He continues with mapping the spoken input to method calls along with their parameters. Then, he concludes: "The linguistic interface might be better, or it might be worse. It comes down to design, and your success will be intimately connected to the application you’re trying to build."

This is exactly the point where voice user interface design comes into play. Each modality requires special design  knowledge for effective interfaces.  Matthew Honnibal seems neither be aware of the term VUI nor of the underlying aproaches and concepts. Maybe, it is time to rediscover it to build better voice-based interfaces employing state-of-the-art NLU technology.

NLU vs Dialog Management

Recently, I stumbled across a blog from api.ai that their system now supports slot filling: https://api.ai/blog/2015/11/09/SlotFilling/. Note, that my goal is not on blaming their system.

Currently, I observe that efforts towards spoken interaction coming from cognitive computing are still not fully aware of what has been done in dialog management research in the past decades, and vice versa. Both parties are coming from different centers in the chain of spoken dialog systems.

While the AI community usually focuses on natural language understanding (linguistic analysis) the spoken dialog community focuses on the dialog manager as the central point in this chain.

Both have good reasons for their attitude and are able to deliver convincing results.

Cognitive computing sees the central point in the semantics which should also be grounded with previous utterances or external content. Speech input and output is in this view restricted to be some input into the system and some output. Dialog management can be really dumb in this case. Resulting user interfaces are currently more or less based on queries.

The dialog manager focused view regards the NLU to be some input into the system while the decision upon subsequent interaction is being handled in this component. Resulting user interfaces range from rigid state-based approaches over the information state update approach up to statistical motivated dialog managers like POMPD.

My hope is, that both communities start talking to each other to better incorporate convincing results of "the other component" to arrive at a convincing user experience.