Author: Andreas Lommatzsch
Chatbots are a popular technique for building a scalable and easy-to-use solution answering user questions. Bobbi is the chatbot of the City of Berlin. The bot is designed for answering questions related to the services provided by the city administration.
With the spread of the SARS-CoV-2 virus and the related COVID-19 disease, questions related to the virus have become a major issue. Citizens frequently demand virus-related information and ask about the most recent regulations.
The development of a component optimized for answering COVID-19 related questions raised several challenges:
- The topic COVID-19 is as recent such that no large training data collections exist.
- The virus affects a lot of different domains. Thus, several different departments and ministries provide information that is relevant for answering user questions.
- The information related to the virus is continuously changing. Thus, the answers must be frequently updated to ensure that all answers are based on the most recent state of information.
- Government agencies provide diverse data. Answers to questions may consist of only one word; other answers are very long and consist of more than 15 sentences.
- The answers provided by the chatbot must be correct. The risk of giving the wrong answer must be minimized.
Our chatbot framework provides a component that fulfills these requirements. A web crawler collects FAQ data from a list of defined sources, such as Berlin’s COVID-19 website, the relevant Berlin’s Senate Administration, and the RKI (Robert-Koch-Institute). The information is re-crawled several times a day ensuring that the information is always up to date.
When a citizen asks a question in the Bobbi chat, the chatbot first checks whether the question is related to COVID-19. If the question is related and the question is very similar to a question available in the set of FAQs, the bot directly provides the answer.
If the question is related but does not exactly match a question from the set of crawled FAQs, the bot shows the user a list of the closest matches. This ensures that even though the user question contains synonyms or a negation, the bot provides a correct question-answer pair. The matching uses a German-language model and a collection of domain-specific synonyms for ensuring a good answer quality without the need for extensive training data.
In addition to the FAQ matching, the bot also searches for relevant administrative services to ensure that the user has access to comprehensive information. The question answering is available in nine different languages.
The chatbot’s usage statistics emphasize the high demand for COVID-19 information. In May 2020, Bobbi conducted about nine times more dialogs compared to the number of dialogs in January 2020. About 80% of the dialogs only consist of questions related to COVID-19.
Due to the high acceptance of this functionality, we will extend this feature so that questions from other topics and domains can be also answered in a similar style.
You can find the chatbot Bobbi on Berlin’s Official Services Web Portal.
