In this chapter, we will give a brief description to the main types of networks (with emphasis on social networks), structural properties of networks, basic concepts in graph theory, a historical background showing how social network analysis developed over years, the most important measures used in SNA and finally examples for SNA modeling tools that are used today by researchers of the field.

In this chapter, the main phases of research design are exhibited, starting from data sampling techniques (examples include snow ball network sampling and egocentered sampling), data collection methods (techniques such as questionnaires and interviews etc. are discussed), and data visualization (where graphs, trees and matrices are explained in some detail). However, data analysis which is the last step in research design will be addressed, later, in chapter 4.

Social network analysis has been used to enhance the performance or to solve problems of a wide range of applications such as semantic Web, social recommender systems, group formation etc. In this chapter we are going to address the main fields that SNA has contributed in their development. We will present the main contribution and summary of work for researchers in each field.

In this chapter, we are going to apply specific techniques of SNA to analyze the BX-dataset (The data that was crawled from the Book Crossing website in 2004) (Fig. 19) and dig out some results such as most positively-rated books (most popular books) and most active users and so on. Then, we are going to conduct the analysis of the user-user network, a sub-network that generates from partitioning the userpreference network. The analysis will take us to apply techniques related to centrality degrees to discover most important figures in that sub-network, in addition to the egonetwork analysis and the m-slice analysis.

In this chapter we will summarize the main concepts that have been addressed throughout this book such as what is SNA, the different types of networks, properties of networks, concepts of graph theory, SNA modeling tools, uses of SNA and other topics with extreme brief. Then we will summarize our main findings that provide answers to questions such as who are the top ten users in the Book Crossing community and what are the top ten popular books and so on.