1. SOCI 5013: Advanced Social Research: Network Analysis Spring 2004

2. Network Studies International Network for Social Network Analysis (INSNA) Academic journals Connections Social Networks

3. Basic Concepts Atomistic approach: individual actors behave without regard to other actors But the nature of the relationships a given actor has with other system members affect focal actor’s perceptions, beliefs and action Explain individual actions in terms of the social contexts they are embedded. SOCI5013: Spring 2004

4. Attributes and Relations Attributes: intrinsic characteristics of people, objects, or events. Occupation’s average income, a nation’s gross national product, a person’s opinion about the president Relations: an emergent property of the connection or linkage between units of observation.

5. Attributes versus Relations Personal attributes (age, sex, intelligence, income) persist independently of social contexts. Relations are contextual specific and will alter or disappear when an actor is removed from interaction with the relevant other parties.

6. Combining Attributes with Relations Social network studies combine attributes with relations to analyze social phenomenon The structure of informal friendships and antagonisms in formal work groups can affect both group and individual productivity rates in ways not predictable from individual attributes such as age, work experience, and intelligence.

7. Networks Social network: a specific type of relation linking a defined set of persons, objects, or events. Different types of relations identify different networks, even when imposed on the identical set of elements. In a set of employees at a workplace, the formal authority network is very different from friendship network.

8. Network Structures Network structures vary in form Some are very isolated structures comprising actors without connections to each other Some are saturated structures with everybody connects to everybody else. But most social networks lie somewhere in between from total isolation to saturation.

9. Attribute Limitation Traditional explanatory factors such as individual or group level attributes only explain a portion of variations in many social phenomenon Network contexts and configurations added significantly to the explained variance in those social phenomenon Technology diffusion is linked not only to person’s education level, but also to that person’s position within a network

10. Research Design Elements Sampling units: individuals, groups, complex formal organizations, classes and strata, communities, nation-state Multi-level units: a corporation with many different departments and employees, a city with many firms and residents

11. Forms of Relations Relational contents: the substantive type of relation represented in the connections (supervising, gossiping, or terrorist planning) Relational forms: properties of the connections between pairs of actors Relational forms include intensity/strength of the relations and involvement of participants.

12. Relational Content Transaction relations Communication relations Boundary penetration relations: interlocking board directors Instrumental relations: Sentimental relations: Authority/power relations Kinship/descent relations

13. Levels of Analysis Ego-centered network: each individual node and all others with which it has relations. Data collection for ego-centered network: ask respondents to name five of his/her best friends, and vital statistics of those friends If there are N actors, total number of cases is N

14. Dyad Dyad: a pair of nodes If there are N actors, the maximum number of sample size is C N 2 = N!/(2!*(n-2)!) Variation in dyadic relations as a function of joint characteristics of the pair Similarity in voting between a pair of person is related to their friendship

15. Complete Network Investigating patterns of ties among all actors to ascertain the existence of distinctive positions or roles within the system and to describe the nature of relations among these positions. Purpose is to assess causes and consequences of network configurations

16. Complete Network Complete network analyses gain popularity in academics recent years Two scientist communities share similarities in individual attributes, dyadic interactions One community is highly fragmented, scientists form small cliques and divisions occur among those cliques One community is highly integrated, scientists forms groups that inter-penetrate other groups Which one has higher rate of knowledge diffusion?

17. Structures in Complete Networks The regular pattern of relations among the positions composed of concrete actors constitutes the social structure of a complete network Main task is to use network relations to map the empirical actors into the latent positions.

18. Network Positions Two methods to map network positions Social cohesion: actors are aggregated together into a position to the degree they are connected directly to each other by cohesive bonds Structural equivalence: actors are aggregated into a joint occupied position to the extent that they have a common set of linkages to the other actors in the system.

19. Graphs Cohesion Structural equivalence A1 A3 A2 A1 A3 A2