Artificial IntelligenceCommand MatchingMachine LearningNatural Language

AI for Voice to Action – Part 2: Machine Learning Algorithms

By October 23, 2018 No Comments
Poison Bottle

My last post discussed the important step of automatically generating vast amounts of relevant content relating to commands to which we apply our machine learning algorithms. Here I want to delve into the design of our algorithms.

Given a command, our algorithms need to:

  1.   Understand the meaning and intent behind the command
  2.   Identify and extract parameters from it
  3.   Determine which app action is most appropriate
  4.   Execute the chosen action and pass the relevant parameters to the action

This post and the next one will address point 1. The other points will be covered in subsequent posts.

So how do we understand what a user means based on their command? Typically commands are short (3 or 4 terms), which makes it very difficult to disambiguate among the multiple meanings a term can have. So if someone says “search for Boston” do they want directions to a city or do they want to listen to a rock band on Spotify? In order to disambiguate among all the possibilities we need to know if a) any of the command terms can have different meanings, b) what those meanings are and finally c) which is the correct one based on context.

Semiotics

In order to do this we developed a suite of algorithms which feed off the data we generated previously (See post #3). These algorithms are inspired by semiotics, the study of how meaning is communicated. Semiotics originated as a theory of how we interpret the meaning of signs and symbols. Given a sign in one context, for example a flag with a skull and crossbones on it, you would assign a particular meaning to it (i.e. Pirates).

Pirate Symbol

Whereas, if you changed the context to a bottle, then the meaning changes completely

Poison Bottle

Poison – do not drink!

Linguists took these ideas and applied them to language and how, given a term (e.g. ‘window’), its meaning can change depending on the meaning of the words around it in the sentence (meanings could be physical window in a room, software window, window of opportunity, etc.).  By applying these ideas to our data we can understand the different meanings a term can have based on its context.

Discourse Communities

We also drew inspiration from discourse communities. A discourse community is a group of people involved in and communicating about a particular topic. They tend to use the same language for important concepts (sometimes called jargon) within their community, and these terms have a specific, understood and agreed meaning within the community to make communication easier. For example members of a cycling community have their own set of terms that is fairly unique to them that they all understand and adhere to. If you want to see what I mean, go here and learn the meanings of such terms as an Athena, a Cassette, a Chamois (very important!) and many other terms. Similarly motor enthusiasts will have their own ‘lingo’. If you want to be able to differentiate your AWS from your ABS and your DDI from your DPF then get up to speed here.

Our users use apps, so in addition we would expect to discover gaming discourses, financial discourses, music discourses, social media discourses and so on. Our goal was to develop a suite of machine learning algorithms which could automatically identify these communities through their important jargon terms. By identifying the jargon terms we can build a picture of the relationship between these terms and other terms used by each discourse community within our data. A characteristic of jargon words is that they have a very narrow meaning within a discourse compared to other terms. For example the term ‘computer’ is a very general term that can have multiple meanings across many discourses – programming, desktop, laptop, tablet, phone, firmware, networks etc. … ‘Computer’ isn’t a very good example of a jargon term as it is too general and broad in meaning. We want to identify narrow, specific terms that have a very precise meaning within a single discourse, e.g. a specific type of processor, or a motherboard. Our algorithms do a remarkable job of identifying these jargon terms and are foundational to our ability to extract meaning, precisely understand user commands and thereby the real intent that lies behind them.

In my next post I will go into the details behind the algorithms that enable us to identify these narrow-meaning, community-specific jargon terms and ultimately to build a model that understands the meaning and intent behind user queries.

David Patterson

Author David Patterson

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