Understanding intents and entities

TIP

Technology plays a role, but the most significant performance gains are obtained by developping a deep understanding of the fundamental NLU concepts.

Intents

An intent captures the general meaning of a sentence (or an utterance in the chatbots lingo). For example, the sentences below convey the intent of being hungry, let's call it i_am_hungry:

  • I am hungry
  • I need to eat something
  • I am starving
  • My kingdom for a pizza

How do we teach our model that those utterances convey the i_am_hungry intent? We train it to distinguish those sentences from sentences with other meanings. We create a dataset containing examples for different intents.

Here is a sample of a dataset in Botfront. You can see examples for 2 different intents. This project has more than 150.

We said that intents carry the meaning of a sentence. How does a progam understand meaning? Let's just say there's a way to express the meaning of words with numbers (or vectors). The long explanation is here if your interested

TIP

Rasa's Tensorflow Pipeline (only pipeline currently supported) only look at those vectors to determine the meaning of words and sentences. Entites present in an utterance won't influence intent classification. It is not necessary to tag entity to help the model pick up the correct intent

Usually, an intent carries an action or an expectation.

Entities

Entities are positional elements in an utterance. In the following examples, we're trying to build a currency exchange assistant. To provide a rate, we need the know which currency the user wants to buy, and which currency she wants to sell.

We have thus 2 entities: currency_buy and currency_sell.

BEST PRACTICE

We have thus 2 entities: currency_buy and currency_sell, and they can have any currency as value. It is important to keep the entity name as generic as possible.

NOT GOOD

A common mistake is to choose the entity value as the name like this:

Last Updated: 5/3/2019, 1:22:17 PM