How are design patterns concerned by developers?

In recent years, design pattern has become an accepted concept in software design and many studies have involved various aspects of design patterns. However, it is an open question that how design patterns are discussed by developers. In this study, we conduct an empirical study to answer this question by soliciting Stack Overflow. First we build a new open catalog with 425 design patterns. Then, we extract 187,493 design pattern relevant posts from Stack Overflow. As to these posts, we find that the popularity of design patterns follows a long tail distribution. More surprisingly, nearly half of the posts focus on only five design patterns. We also successfully detect many potential new co-occuring design patterns, which could well complement the deficiency of existing studies.