Contextual short-term memory for LLM-based chatbot

Sammanfattning: The evolution of Language Models (LMs) has enabled building chatbot systems that are capable of human-like dialogues without the need for fine-tuning the chatbot for a specific task. LMs are stateless, which means that a LM-based chatbot does not have a recollection of the past conversation unless it is explicitly included in the input prompt. LMs have limitations in the length of the input prompt, and longer input prompts require more computational and monetary resources, so for longer conversations, it is often infeasible to include the whole conversation history in the input prompt. In this project a short-term memory module is designed and implemented to provide the chatbot context of the past conversation. We are introducing two methods, LimContext method and FullContext method, for producing an abstractive summary of the conversation history, which encompasses much of the relevant conversation history in a compact form that can then be supplied with the input prompt in a resource-effective way. To test these short-term memory implementations in practice, a user study is conducted where these two methods are introduced to 9 participants. Data is collected during the user study and each participant answers a survey after the conversation. These results are analyzed to assess the user experience of the two methods and the user experience between the two methods, and to assess the effectiveness of the prompt design for both answer generation and abstractive summarization tasks. According to the statistical analysis, the FullContext method method produced a better user experience, and this finding was in line with the user feedback.