Chatbots are becoming an attractive tool for people who seek medical advice due to their constant availability. Multiple healthcare chatbots were developed for different purposes such as delivering advice, booking appointments, and accessing medical records. Additionally, it was found that personalized healthcare chatbots affected the user experience positively, due to the addition of human empathy. Therefore, we propose building a character-based chatbot named “Chasey” for COVID-19, to combat the risk of misinformation amplification during the pandemic. Chasey provides users with various COVID-19 information such as tracking the cases per country, giving advice, answering frequently asked questions, and performing symptoms checking. According to the selected chatbot character, users will receive personalized responses to their inquiries from verified sources. Moreover, we investigate how our chatbot implementation overcomes some of the challenges and limitations of healthcare and COVID-19 chatbots. Finally, an experiment was conducted to evaluate the chatbot's usability, as well as, the likability and trustworthiness of the chatbot characters. Overall, the participants were satisfied with the chatbot features and character change option. Moreover, significant results were found between the likability of the chatbot characters.

Ontologies represent the backbone of the semantic web since they represent knowledge in a machine-understandable way. The more complex the ontologies are, the greater is the need for visualization tools to ease the understanding of the large amount of knowledge represented by these ontologies. Visualizing large ontologies is a still under-investigated interesting challenge. In this paper, we present VisCOnto, a visualization tool of complex ontologies by extracting sub-ontologies that correspond to excerpts of a large ontology focusing on some concepts of interest. VisCOnto combined with WEBVOWL can create sub-ontologies to create expressive information visualizations by harnessing the semantic reasoning capabilities provided by ontologies. A proof of concept use case for applying VisCOnto to visualize an existing complex ontology of human behavior and character is presented.