At this years’ SIGdial conference, researchers from the Technical University of Munich, department of informatics published a paper entitled “Evaluating Natural Language Understanding Services for Conversational Question Answering Systems”.
The team compared performance between four services – LUIS, Watson, API.ai and RASA, by provisioning each service using large data sets of questions. The data was gathered from multiple sources, a Telegram production chatbot, and two StackExchange platforms – ask ubuntu, and Web Applications. All of the services were provisioned and trained with exactly the same data.
Check it out: http://www.sigdial.org/workshops/conference18/proceedings/pdf/SIGDIAL22.pdf