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2: Why Formal Methods?

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The basic idea of a social network is very simple. A social network is a set of actors (or points, or nodes, or agents) that may have relationships (or edges, or ties) with one another. Networks can have few or many actors, and one or more kinds of relations between pairs of actors. To build a useful understanding of a social network, a complete and rigorous description of a pattern of social relationships is a necessary starting point for analysis.

• 2.1: Introduction
The amount of information that we need to describe even small social networks can be quite great. Managing these data, and manipulating them so that we can see patterns of social structure can be tedious and complicated. All of the tasks of social network methods are made easier by using tools from mathematics. For the manipulation of network data, and the calculation of indexes describing networks, it is most useful to record information as matrices. For visualizing patterns, graphs are oft
• 2.2: Efficiency
One reason for using mathematical and graphical techniques in social network analysis is to represent the descriptions of networks compactly and systematically. This also enables us to use computers to store and manipulate the information quickly and more accurately than we can by hand.
• 2.3: Using computers
A related reason for using (particularly mathematical) formal methods for representing social networks is that mathematical representations allow us to apply computers to the analysis of network data.
• 2.4: Seeing patterns
The third, and final reason for using "formal" methods (mathematics and graphs) for representing social network data is that the techniques of graphing and the rules of mathematics themselves suggest things that we might look for in our data — things that might not have occurred to us if we presented our data using descriptions in words
• 2.5: Summary
There are three main reasons for using "formal" methods in representing social network data. For example, matrices and graphs are compact and systematic. They summarize and present a lot of information quickly and easily; and they force us to be systematic and complete in describing patterns of social relations. Matrices and graphs allow us to apply computers to analyzing data. And Matrices and graphs have rules and conventions.