In this lesson, you will learn how to create synonyms for your slots using entity resolution.

Use Synonyms in Voice Interaction

Imagine you are creating a skill where a user can ask Alexa for a recommendation for a pet based on a size preference. The dialog may look something like:

_USER: ask pet match to find me a `big` dog._ <br>
_ALEXA: The Great Dane is an example of a big dog._

In this case, your skill would accept the word `big` as a slot value. Other values may include: `small` and `medium`. Your skill captures the word "big" as the slot value and passes it on to your AWS Lambda function, so your skill can respond with "The Great Dane is an example of a big dog."

#### A Bad Example

Now, what would happen if the user said, "ask pet match to find me a `large` dog." As humans, we know that large means almost the same thing as big. Your current skill, however, cannot differentiate between these inputs.

In this lesson, you will learn how to address problems like the one above by creating *synonyms* for your slot values. Synonyms allow a user to speak in a way that makes sense for them, while providing a means for your skill to correctly interpret the user's input. 

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This course assumes you are comfortable making Alexa Skills with the Alexa Developer Console and AWS Lambda. If you're not, start with our <a href="https://www.codecademy.com/learn/learn-alexa" target="_blank" rel="noopener noreferrer">Learn Alexa course</a> and come back when you're ready!


Why Use Synonyms

Let's see what happens when the user says a word that is not included in our slot synonyms list. Try typing something like:

- "ask movie match to find me pizza movie"
- "ask movie match to find me taco movie"
- "ask movie match to find me alfredo movie"
  

#### Inspecting the JSON Input

Scroll down to the `resolutions` object. The value that we used, `taco`, did not resolve to any slot value. We know this because the `resolutions` node contains the status code of `ER_SUCCESS_NO_MATCH`. Also, the resolutions node doesn't include a `value` field. 

As you can probably tell, you could use the status code and the presence of the `values` object inside `resolutions` to respond back to the user appropriately. 



Entity Resolution No Match

In this exercise, you will learn how to test synonyms in your Alexa skill.

#### Make a dummy endpoint
1. In the <a href="https://developer.amazon.com/alexa-skills-kit?&sc_category=Earned&sc_channel=RD&sc_campaign=EntityResolution&sc_publisher=Codecademy&sc_content=Content&sc_detail=Design_Course&sc_funnel=Visit&sc_country=WW&sc_medium=Earned_RD_EntityResolution_Codecademy_Content_Design_Course_Visit_WW_AdvancedDevs&sc_segment=AdvancedDevs" target="_blank" rel="noopener noreferrer">Amazon Developer Console</a>, click on the _Build_ tab, then select the Endpoint section in the left sidebar. In this section, select HTTPS, and type in `https://example.com` in the Default Region only. (We will be creating a real endpoint on AWS Lambda later, but for now, we don’t really need it). 
2. For the **SSL Certificate Type**, select the second option: _"My development endpoint is a sub-domain of a domain that has a wildcard certificate from a certificate authority"_
3. Click _Save Endpoints_ button at the top of your screen.

#### Testing our Synonyms
Try matching a synonym to the slot value using the steps below.
1. Click on the _Test_ tab in the header.
2. Make sure testing is enabled for your skill by selecting the toggle in the top left corner of the web page.
3. In the Alexa Test Simulator panel &mdash; type, `ask movie match to find me a combat movie` and press enter. Remember we had added combat, battle, fight, war as the synonyms for the slot value of action.
4. Alexa will respond with "There was a problem with the requested skill's response", and the JSON Output would be 'null'. This is expected behavior since our endpoint (`https://example.com`) isn't real.
5. More importantly, you will see JSON Input, that was generated for your skill (similar to one on the right) based on the user request. Let’s inspect this JSON to check if the synonym was resolved successfully.

#### Inspecting the JSON Input

If you scroll down to the request property in the JSON input, you will see that there is an object called `resolutions` which contains some additional information relevant to our slots. The value that we used, `combat`, successfully resolved to the slot value `action`. We know this because the `resolutions` node contains the status code of `ER_SUCCESS_MATCH`. `ER` in `ER_SUCCESS_MATCH` stands for Entity Resolution. The status code indicates the skill successfully matched the synonym (`combat`) to the slot value (`action`). 

Additionally, in the `values` node, you can see that the IntentRequest still passes `action` as the value.


Testing: Synonyms

In the <a href="https://developer.amazon.com/docs/devconsole/test-your-skill.html#test-simulator?&sc_category=Earned&sc_channel=RD&sc_campaign=EntityResolution&sc_publisher=Codecademy&sc_content=Content&sc_detail=Design_Course&sc_funnel=Visit&sc_country=WW&sc_medium=Earned_RD_EntityResolution_Codecademy_Content_Design_Course_Visit_WW_AdvancedDevs&sc_segment=AdvancedDevs" target="_blank" rel="noopener noreferrer">Alexa Test Simulator</a>, take some time to try a few more synonyms and the slot value itself (action). 

Did your JSON responses look similar to the image on the right?

Notice, the JSON input resolves to `action` for all successful matches. This is the purpose of entity resolution:
It allows us to create synonyms for our slot values so that we can receive consistent data in our code, but still allows a user to speak in the way that makes sense for them.

Before synonyms, you would have to catch all of those words as slot values, compare them to a group of values in your code, and determine which movie genre to return to the user.

For example, if the status code is `'ER_SUCCESS_NO_MATCH'`, your skill could respond with something like:

_ALEXA: Sorry, I don't know any `taco` movies, but I can add that as a feature request. Would you like to search by `action`, `comedy`, or `drama`?_


Entity Resolution Explained

To resolve the issue of mapping `large` to `big`, we can use synonyms in the Alexa Skills Kit to create a sort of custom thesaurus for our skill. For example, we could map `small`, `medium`, and `big` to the following synonyms:

| Value  | Synonyms                 |
| ------|--------------------------|
| big    | large, huge, gigantic    |
| medium | intermediate, in between |
| small  | tiny, mini               |

Using synonyms in the Alexa Skills Kit is a great way to improve the voice design of your Alexa skill, and add flexibility to the user interaction. 

In the next few exercises, you will learn how to create synonyms for your own skill that maps a user's movie preferences to a specific genre, then recommends a movie to watch within that genre.  



Using Synonyms

Nice work! You just learned how you can use synonyms to allow a user to speak in a natural way.

Let's review what we learned: 

- Using synonyms is a great way to improve the voice design of your Alexa skill, and add flexibility to the user interaction.
- You add synonyms for your slots through the <a href="https://developer.amazon.com/docs/custom-skills/use-the-skill-builder-beta-to-define-intents-slots-and-dialogs.html?&sc_category=Earned&sc_channel=RD&sc_campaign=EntityResolution&sc_publisher=Codecademy&sc_content=Content&sc_detail=Design_Course&sc_funnel=Visit&sc_country=WW&sc_medium=Earned_RD_EntityResolution_Codecademy_Content_Design_Course_Visit_WW_AdvancedDevs&sc_segment=AdvancedDevs" target="_blank" rel="noopener noreferrer">Skill Builder</a> on Amazon Developer Console.
- The synonym and the resolved value are passed to your skill through the JSON request.
- If what the user said is successfully matched to one of the synonyms, the `resolutions` node in the JSON request contains the status code of `ER_SUCCESS_MATCH`.
- If what the user said is not successfully matched to any of the synonyms, the `resolutions` node in the JSON request contains the status code of `ER_SUCCESS_NO_MATCH`.
- ER in `ER_SUCCESS_MATCH` stands for Entity Resolution.
- Alexa's <a href="https://developer.amazon.com/docs/custom-skills/define-synonyms-and-ids-for-slot-type-values-entity-resolution.html?&sc_category=Earned&sc_channel=RD&sc_campaign=EntityResolution&sc_publisher=Codecademy&sc_content=Content&sc_detail=Design_Course&sc_funnel=Visit&sc_country=WW&sc_medium=Earned_RD_EntityResolution_Codecademy_Content_Design_Course_Visit_WW_AdvancedDevs&sc_segment=AdvancedDevs" target="_blank" rel="noopener noreferrer">Entity Resolution</a> allows us to create synonyms for our slot values so that we can receive consistent data in our code, but still allows a user to speak in the way that makes sense for them.





Review

In this exercise, we will walk you through the steps to create a new skill and add synonyms to the values for a `MOVIE_GENRE` custom slot type. If you need a refresher on how to create a skill, you should look at Codecademy's <a href="https://www.codecademy.com/courses/learn-alexa-skills-kit/lessons/intro-to-alexa/exercises/skill-builder-interaction-model?action=resume_content_item&course_redirect=learn-alexa" target="_blank">Build Your First Skill</a> course.


The video to the right shows you how to create this slot and add synonyms (steps 5-8) in the <a href="https://developer.amazon.com/alexa-skills-kit?&sc_category=Earned&sc_channel=RD&sc_campaign=EntityResolution&sc_publisher=Codecademy&sc_content=Content&sc_detail=Design_Course&sc_funnel=Visit&sc_country=WW&sc_medium=Earned_RD_EntityResolution_Codecademy_Content_Design_Course_Visit_WW_AdvancedDevs&sc_segment=AdvancedDevs" target="_blank" rel="noopener noreferrer">Amazon Developer Console</a>.

1. Create a new skill called `Movie Match`
2. Choose Custom model to add to your skill
3. Type the invocation name 'movie match'
4. Create a new slot type called `MOVIE_GENRE`
5. Create these values for the `MOVIE_GENRE` slot type &mdash; `action`, `comedy`, `horror`, and `drama`. 
6. Click the "Add synonym" input field for your action slot value, and type each of its synonyms, like `fight`, `battle`, `combat`, `war` etc. Press enter after each. Note: The optional ID field is not necessary.
7. Do the process described in step 6 for `comedy`, `horror`, and `drama` slot values as well.
8. Create a new intent called `FindMovieByGenreIntent`
9. Add the sample utterance, `find me a {genre} movie`. 
10. In the section titled "Intent Slots" at the bottom of the page, choose the Slot Type `MOVIE_GENRE` for the `genre` slot.
11. Save and Build your model. 

_Important: Wait until the model built before you proceed to the next step. This may take a few minutes._
<br>

Congrats! You successfully created the synonyms. In the next exercise, you will learn how to test your skill.



