Dialogue response generation is an important AI research topic. We are investigating this topic with the open domain perspective, meaning the topics of the dialogues are not pre-specified. I describe a new model called Variable Hierarchical User-based Conversation Model which considers the previous dialogues among users, as well as their social network connections. I then describe a new evaluation metric called Speaker Sensitive Response Evaluation Model which correlates better with human judgments. These are described in our recent EMNLP 2019 and ACL 2020 papers.