Differences between using Lex and Alexa

Question

I'm building an Alexa skill that will allow Alexa users to interact with a consumer facing e-commerce site. There is functionality to call a representative that already exists on the site. Now, I want to build out a voice app as a side project that extends that same option via a conversation. There will be a need for slots like location, category of call, etc. It's basically an Application/Transactional bot.

In the future, if this is successful, I'd like that same general app to be accessible on different IoT devices (like Google Home Assistant, etc.) Therefore, I'd like to abstract out the voice interactions and have the same (general) flow and API to interact with.

This leaves me doing some research on different technologies like api.ai, wit.ai, Lex, etc.

But, since this is an app for Alexa and I already rely on AWS and Amazon in general, I think I'd prefer to use Lex or just write a native Alexa app for now.

I'm having a hard time understanding the differences between the two. I understand that Alexa was built using Lex and I see that they have similar concepts like intent, slots, etc.

But, I'm looking for any differences between the two services:

1. Would using Lex allow me to more easily integrate with other devices? Or is there any benefit?

2. Would using Lex allow me greater flexibility in designing/modifying the flow of a conversation? It seems like Lex is a little more complex and, therefore, might allow greater functionality.

3. Or is it just that Lex offers nearly the exact same functionality and is just meant for devices that aren't Alexa?

4. Does Lex offer any more analytics processing than Alexa? In Alexa I can only see intents/slots, but if I could see the actual text in Lex, that would be ideal.

Answer 1

Alexa Skills Kit (ASK) is used to build skills for use in the Alexa ecosystem and devices and lets developers take advantage of all Alexa capabilities such as the Smart Home and Flash Briefing API, streaming audio and rich GUI experiences. Amazon Lex bots support both voice and text and can be deployed across mobile and messaging platforms.

Lex Faqs

Answer 2

In my view (very limited Alexa dev experience) AWS Lex allows greater control over the bot dialog. It defines separate validation and fulfilment code hooks, enables specific prompts for slots on the UI, supports programmatic transitions between intents, gives proper versioning and alias handling, etc... so it seems it's more of an enterprise offering as opposed to "consumer-level" Alexa skills.

But surprisingly it lacks a few important features, e.g. it does not have a built in "boolean" slot type, so you have to code around yes/no questions. Or there are no Cloudwatch logs for lex at all. Also the (growing) list of integrations will make it more generic.

But despite being a huge AWS fan, I have to say that api.ai seems to be a reasonably more polished, feature rich proposition at least for now.

With regards to integrations with other devices, I do not think any of these platforms promise that. It seems that if you target Google home, than it's their platform, if you target Alexa, then hmm it's alexa or api.ai (not sure if Google will push this in the future). But if you plan to integrate with chat platforms, or directly into web applications, then I think all major platforms can give you that, or in the near future.

By the way, have you checked IBM Watson or Microsoft Bot framework (with LUIS)? They are also very capable, complete frameworks, too, don't discount them!

Answer 3

There is a risk using an external NLP service to process raw text delivered by Alexa over its native hobbled interaction model. Amazon may not certify your skill. This is unfortunate to hear, but their excuse is the threat of exposing private user data users may not realize they're sending. This is sickening because to do anything robust you must avoid Alexa's native NLP system. And I don't believe LEX is advanced much beyond it. You're caught in a bind. This is what will set Alexa back perhaps in the long run with respect to natural conversation. We've been preparing our skis in stealth mode, and an Amazon rep said our approach was a "hack" and may not get certification when published. I'm not yet sure what the answer is. Does this raw text issue exist with Google Home or other voice platforms? Beware.

Answer 4

"Alexa for Business is intended to enable organizations to take advantage of Amazon’s voice enabled assistant, Alexa. Alexa for Business provides Alexa capabilities that make workers more productive, while working alongside all of the other capabilities that Alexa has today like music, smart home controls, shopping, and thousands of third party skills.

Amazon Lex is intended to help build custom conversational interfaces and chat bots for use cases like call centers or application based bots. Bots built with Lex can be highly customized and exist separately from Alexa but they do not take advantage of Alexa’s built in capabilities or third party skills. Both Alexa for Business and Amazon Lex use Amazon’s deep learning capabilities that provide Automatic Speech Recognition (ASR) and Natural Language Understanding (NLU)."