演講內容:A social network is a social structure made of individuals (or organizations) called "nodes," which are tied (connected) by one or more specific types of interdependency, such as friendship, kinship, financial exchange, dislike, sexual relationships, or relationships of beliefs, knowledge or prestige. Social network analysis (SNA) views social relationships in terms of network theory consisting of nodes and ties. Currently more and more social activities are performed on Internet. In this talk, I shall introduce the basic of SNA and some issues in SNA, especially the ones on Internet. Examples will be included