A third way to deal with the cold start problem is to use active learning and feedback techniques, which can help you acquire more relevant and informative data from users or items in an efficient and interactive way. For example, you can use active learning strategies, such as uncertainty sampling, diversity sampling, or expected utility, to select the most valuable users or items to query or recommend, based on the uncertainty, diversity, or utility of their ratings or feedback. Alternatively, you can use feedback techniques, such as explicit ratings, implicit signals, or conversational agents, to collect more data from users or items, based on their preferences, behavior, or interaction. These techniques can help you increase the data quality and quantity and improve the learning and recommendation of your recommender system.