Soc 712 Seminar on Social Networks
Professor: James Moody



Meeting Time: M W, 1:30 – 3:18
Office Hours: W 3:30 – 5:30
Place: Derby 70 (SIL).

“To speak of social life is to speak of the association between people – their associating in work and in play, in love and in war, to trade or to worship, to help or to hinder.  It is in the social relations men establish that their interests find expression and their desires become realized.”
                            -- Peter M. Blau, 1964


Overview:

This seminar focuses on theoretical and substantive themes within social network analysis.  The theoretical heart of this approach to social science is that actors are interdependent, and that social structure emerges from regularities in this interdependence.  In this seminar, we will couple the substantive and theoretical development of social network analysis with methodological tools to implement network research.  By the end of the course, you should (1) know the major theoretical ideas supporting network research, (2) be able to collect social network data and, (3) be able to analyze and interpret social network data. 

Social network research is unique in the extent to which methodological tools derive directly from substantive theories.  As such, class time will be split almost 50-50 on methodological and substantive (theory, application, and examples) issues, with each substantive topic tied to a new method or analysis strategy.  Substantive topics will include work on sexual behavior, organizational performance, delinquency, power, friendship, and much more.


Requirements:

The main requirement of this seminar is a research paper that uses the methods or ideas of social network analysis.  This may be a revision of previous work (an MA paper, another course paper, etc.) or a new paper.   If this is a revision of a previous paper, you need to show that the addition of network ideas or methods significantly contributes to the revision.  You may collaborate with up to 2 other students (3-authors total) on your final paper.  The second requirement for the class is a set of homework assignments designed to build familiarity with the software and analysis techniques.  Assignments will be largely self-graded, with the solutions posted on the web page.  Finally, since this is a seminar, in-class participation is necessary.  The requirement breakdown will be roughly as follows:

·         Final paper: 65%

·         Homework: 30%

·         Class Participation: 5%

Texts:

The main text for the class is Wasserman and Faust (1994): Social Network Analysis. Cambridge University Press.  This book will provide the main methodological and background reading for the course. You should also read either: Linked: The New Science of Networks by Albert-László Barabási,  as an introduction to the science of networks or The Development of Social Network Analysis by Linton Freeman, on the history of SNA (read one of these by the first class meeting).

Most papers we are reading will be linked to on-line sources from the class web-page version of this syllabus.  Any that we cannot get on-line will be available for copy in a folder outside my office door (372 Bricker).

Software:
You will need access to three pieces of software:

1) UCI-NET. This is the industry standard network analysis program. The most recent version (6) is available for about $40 from Analytic technologies. Orders may be placed by web, mail, telephone, fax, or e-mail. The newest version of the program also includes NETDRAW, a great new program for drawing sociograms.

Analytic Technologies
11 Ohlin Lane
Harvard, MA 01451
USA
Tel: +1 978.456.7372
Fax: +1 978.456.7373
Web: www.analytictech.com
E-mail: sales@analytictech.com

2) Access to SAS, including IML, and a set of programs I have written called SPAN (Sas Programs for Analyzing Networks), which contains a set of useful routines. The program is free, and can be downloaded at my website (http://www.soc.duke.edu/~jmoody77/span/span.zip).

3) PAJEK. A program for analyzing large networks, and arguably the best drawing program on the market. It is free. You can download the most recent version of PAJEK at: http://vlado.fmf.uni-lj.si/pub/networks/pajek/default.htm

Online resources

  1. Class web page: http://www.soc.duke.edu/~jmoody77/s884/index.htm
  2. International Network for Social Network Analysis (INSNA) home page http://www.heinz.cmu.edu/project/INSNA/
  3. Steve Borgotti’s network Page http://www.analytictech.com/networks/


Schedule:

By clicking on each of the days, you will be taken to any notes/handouts for that day.

Class 1. Introduction to Social Network Analysis

Summary: First day of class. Discuss syllabus, go over the history of social network research, general trends in the field and some basic elements of how social network data differ from data social scientists are used to collecting.
Reading: Barabasi: Linked or Freeman Development of SNA
Assignments: Family as Social Network & Substantive implications
Background Reading: None

 

Class 2. Foundations of network analysis

Summary: Continue discussion of elementary theory, introduce data structures for organizing social network data. Distinctions between directed, undirected, valued, local and global networks. Basics of Graph Theory.

Reading: Wasserman & Faust, Chapter 1 & 2 (focus on 1st half of chap 2).
(a) Emirbayer, M. 1997. "Manifesto for Relational Sociology." American Journal of Sociology 103:281-317.
or
(b) Wellman, Barry: "Structural Analysis: From method and metaphor to theory and substance" (MoodyOffice)

Assignment: HW2: Matrix manipulations, graph translation exercise, network drawing.

Background Reading:   Borgatti, S.P. "A quorum of graph theoretic concepts" Connections 1994

 

Class 3.  Local Networks

Summary: The building blocks of a network are the sets of relations each person is embedded within. Today we discuss how positions can be defined in terms of the pattern and composition of network alters. We identify sources of such data in the literature and how to manipulate them.

Reading:

Marsden, Peter: "Core discussion networks of Americans" American Sociological Review Vol. 52, No. 1. (Feb., 1987), pp. 122-131
Mizruchi, Mark & Linda Brewster Stearns Getting Deals Done: The Use of Social Networks in Bank Decision-MakingAmerican Sociological Review 2001 66:647-671

Bearman & Parigi “Cloning Headless Frogs and Other Important Matters: Conversation Topics and Network Structure  Forthcoming in Social Forces

 

Assignments: HW2: Matrix manipulations, graph translation exercise, network drawing.

 

Background Reading:

Fischer, Claude: To Dwell Among Friends

Moore, G. 1990. "Structural Determinants of Men's and Women's Personal Networks." American Sociological Review 55:726-35.

Renzulli, L. A., H. Aldrich, and J. Moody. 2000. "Family Matters: Gender, Networks, and Entrepreneurial Outcomes." Social Forces.

van Duijn, M. A. J., J. T. ban Busschbach, and T. A. B. Snijders. 1999. "Multilevel Analysis of Personal Networks As Dependent Variables." Social Networks 21:187-209.
Wellman, B., R. Y. Wong, D. Tindall, and N. Nazer. 1997. "A Decade of Network Change: Turnover, Persistence and Stability in Personal Communities." Social Networks 19(1):27-50.
Wellman, B. and S. Wortley. 1990. "Different Strokes From Different Folks: Community Ties and Social Support." American Journal of Sociology 96:558-88.
(There are hosts of other good pieces using local networks. Most articles in the health field, for example, use local networks, since the data are easy to collect).

 

Class 4.  Local Networks Continued

Summary: The structural patterns in local networks affect the distribution of information and power in that network. Today we focus on identifying the effects of local network configurations and how those configurations fit into wider patterns of relations.

 

Reading:
Burt, R. Structural Holes, Chapter 1. (MoodyOffice)

Burt, R. 2004.  Structural Holes and Good IdeasAmerican Journal of Sociology 110:349-400

Granovetter, Mark. "The Strength of Weak Ties." The American Journal of Sociology, Vol. 78, No. 6. (May, 1973), pp. 1360-1380.

Assignments: Ego-network Characteristics  +  Calculate Burt’s Measures for the example data.

Background Reading:
Lee, Nancy Howell (1969) The search for an abortionist. University of Chicago Press
Granovetter, Mark. (1974) Getting a job; a study of contacts and careers. Harvard University Press

Class 5. Relations through associations.

Summary: People form relations through overlapping associations. In so doing, they not only create a network of people, but also a network of associations. This is captured through the duality of persons and groups, and provides a very powerful way to identify network processes through commonly available data.

 

Reading:

Breiger, R. L. "The Duality of Persons and Groups." Social Forces, Vol. 53 :181-190.

Moody, James. 2004. “The Structure of a Social Science Collaboration Network” American Sociological Review 69:213-264

W&F Chapter 8 (skim).

Assignments: Construct a person-through-groups network, provide basic descriptive statistics for the network.

Background Reading:

Bearman, P. and K. Everett. 1993. "The Structure of Social Protest." Social Networks 15:171-200.

Lots of great work on director interlocks, such as that by Mizruchi.
 

Class 6. Centrality.

Summary: Another conception of "position" in a social network deals with where an actor resides within a network. Falling under the broad heading of centrality, a series of measures are identified that highlight individuals positions in the network.

Reading: W&F Chap. 5.
Bonacich, P. 1987. "Power and Centrality: A Family of Measures." American Journal of Sociology 92:1170-1182.

Assignments: Calculate and compare different measures of centrality on the same network.

Background Reading:

Bell, D. C., J. S. Atkinson, and J. W. Carlson. 1999. "Centrality Measures for Disease Transmission Networks." Social Networks 21:1-21.
Bolland, J. M. 1988. "Sorting Out Centrality: An Analysis of the Performance of Four Centrality Models In Real and Simulated Networks." Social Networks 10:233-53.
Freeman, L. C. 1977. "A Set of Measures of Centrality Based on Betweenness." Sociometry 40:35-41.
———. 1978-1979. "Centrality in Social Networks." Social Networks 1:215-39.
Friedkin, N. E. 1991. "Theoretical Foundations for Centrality Measures." American Journal of Sociology 96:1478-504.
Rothenberg, R. B., J. J. Potterat, W. W. Woodhouse, S. Q. Darrow, S. Q. Muth, and A. S. Klovdahl. 1995. "Choosing a Centrality Measure: Epidemiologic Correlates in the Colorado Springs Study of Social Networks." Social Networks: Special Edition on Social Networks and Infectious Disease: HIV/AIDS 17:273-97.

Class 7. Centrality (continued)

Summary: Continue our work on centrality, focusing on processes of information and disease diffusion.

 

Reading:
Friedkin, N. E. 1993. "Structural Basis of Interpersonal Influence in Groups: A Longitudinal Case Study." American Sociological Review 58:861-72.
or

Aldersen and Beckfield 2004. “Power and Position in the World City SystemAmerican Journal of Sociology 109:811-851


 Assignments:
Background Reading:

Baker, W. E. and R. R. Faulkner. 1993. "The Social Organization of Conspiracy: Illegal Networks in the Heavy Electrical Equipment Industry." American Sociological Review 58:837-60.

Bell, D. C., J. S. Atkinson, and J. W. Carlson. 1999. "Centrality Measures for Disease Transmission Networks." Social Networks 21:1-21.
Bolland, J. M. 1988. "Sorting Out Centrality: An Analysis of the Performance of Four Centrality Models In Real and Simulated Networks." Social Networks 10:233-53.
Bonacich, P. 1987. "Power and Centrality: A Family of Measures." American Journal of Sociology 92:1170-1182.
Freeman, L. C. 1977. "A Set of Measures of Centrality Based on Betweenness." Sociometry 40:35-41.
———. 1978-1979. "Centrality in Social Networks." Social Networks 1:215-39.
Friedkin, N. E. 1991. "Theoretical Foundations for Centrality Measures." American Journal of Sociology 96:1478-504.
Rothenberg, R. B., J. J. Potterat, W. W. Woodhouse, S. Q. Darrow, S. Q. Muth, and A. S. Klovdahl. 1995. "Choosing a Centrality Measure: Epidemiologic Correlates in the Colorado Springs Study of Social Networks." Social Networks: Special Edition on Social Networks and Infectious Disease: HIV/AIDS 17:273-97.

 

Class 8. Connectivity 1.  The Small World Problem.

Summary: Much of the power of networks comes from the inter-connection of local networks into wider populations. Based on what we know of local networks and people’s involvement in activities, what should networks look like at the global level?

Reading:
Travers, J. and S. Milgram. "An experimental study of the small world Problem" Sociometry 32:425-443
Watts, Duncan J. “Networks, Dynamics, and the Small-World PhenomenonAmerican Journal of Sociology. v.1999, 105, 2, Sept, 493-527.

 

Assignments: Small-world connectivity test. How many people do you know?
     Identifying components, reachability, distance.
     Calculating biased network statistics.

 

Background Reading:

Pool, I. d. S. and M. Kochen. 1978. "Contacts and Influence." Social Networks 1:5-51.
Rapoport, A. and W. J. Horvath. 1961. "A Study of a Large Sociogram." Behavioral Science 6:279-91.
Fararo, T. J. 1981. "Biased Networks and Social Structure Theorems." Social Networks 3:137-59.
Fararo, T. J. and J. Skvoretz. 1987. "Unification Research Programs: Integrating Two Structural Theories." American Journal of Sociology 92:1183-209.
Newmann, M. E. J. 1999. Models of the Small World. Online at: http://www.arxiv.org/format/cond-mat/0001118
M. E. J. Newman (2000) Who is the best connected scientist? A study of scientific coauthorship networks. Santa Fe Institute working paper 00-12-064. (online as well).
Watts, Duncan J. 1999. Small Worlds: The Dynamics of Networks between Order and Randomness. Princeton University Press

 

Class 9. Connectivity II: Social cohesion in diffuse settings

Summary: The power of networks to draw communities together rests on the redundancy of social relations. Today we dig deeper into the sources of connectivity and cohesion.

Reading: Moody, James & Douglas R. White (2003) "Structural Cohesion and Embeddedness" American Sociological Review 68:103-127
Bearman, Faris, & Moody, "Blocking the Future" Social Science History 23:501-533

Assignments: Identify cohesion in particular networks, plot components and bi-components from test networks. Describe how cohesion would operate in the substantive area you are working in.

 

Background Reading:

Klovdahl, A. S. 1985. "Social Networks and the Spread of Infectious Diseases: The AIDS Example." Social Science Medicine 21:1203-16.

 

Class 10.  Building Nets from Local Action 1: Social Balance.

Summary: We have now seen the basic structures of informal networks and details of local networks. What interpersonal process could be consistent with both of these features? More important, can we identify a local level mechanism that would generate such structures? Will also introduce the problem of statistical measurement of network attributes.

 

Reading:
Davis, J. A. 1963. "Structural Balance, Mechanical Solidarity, and Interpersonal Relations." American Journal of Sociology 68:444-62.

Doreian, P., R. Kapuscinski, D. Krackhardt, and J. Szczypula. 1996. "A Brief History of Balance Through Time." Journal of Mathematical Sociology 21(1-2):113-31. (MoodyOffice)
W&F chap 6 & 14 (skim 14)

Assignments: Identify transitivity levels in a network, triad distribution.

Background Reading:

Johnsen, E. C. 1985. "Network Macrostructure Models for the Davis-Leinhardt Set of Empirical Sociomatrices." Social Networks 7:203-24.
———. 1986. "Structure and Process: Agreement Models for Friendship Formation." Social Networks 8:257-306.

 

Class 11. Building nets from local action 2: Hierarchy

Summary: Consistent local action can have dramatic global effects. Today we continue our discussion of local balance, focusing on the development of hierarchy and the dynamics of social groups.

 

Reading: Chase, Ivan. "Social process and hierarchy formation in small groups: A comparative perspective." American Sociological Review 45:905-924

Gould, Rodger (2002).  "The Origins of Status Hierarchies: A formal Theory and Empirical Test" American Journal of Sociology. 107:1143-1178

Krackhardt, D. 1994. "Graph Theoretical Dimensions of Informal Organizations." Computational Organizational Theory, Editor Kathleen Carley and Michael Prietula. Hillsdale, N.J: Lawrence Erlbaum Associates. (MoodyOffice)

 Assignments: Calculate hierarchy measures for a network.

 

Background Reading:
 Moody, James. "High School Hierarchy: Stable balance in a dynamic setting" (manuscript available)

 

Class 12. Sub-Groups 1

Summary: Primary groups are common in social interaction. How important are these groups and how do we identify them? We will go over multiple methods for identifying a primary group.

 

Reading: Freeman, L. C. 1992. "The Sociological Concept of "Group": An Empirical Test of Two Models." American Journal of Sociology 98:152-66.
Frank, K. A. and J. Y. Yasumoto. 1998. "Linking Action to Social Structure Within a System: Social Capital Within and Between Subgroups." American Journal of Sociology 104:642-86.
Moody, James. (2001)  "Peer Influence Groups: Identifying dense clusters in large networks." Social Networks 23:261-283

 

Assignments: Identify cohesive groups in test data.

 

Background Reading:

Alba, R. D. 1973. "A Graph-Theoretic Definition of a Sociometric Clique." Journal of Mathematical Sociology 3:113-26.
Burt, R. S. 1987. "Social Contagion and Innovation: Cohesion Versus Structural Equivalence." American Journal of Sociology 92:1287-335.
Fershtman, M. 1997. "Cohesive Group Detection in a Social Network by the Segregation Matrix Index." Social Networks 19:193-207.
Frank, K. A. 1995. "Identifying Cohesive Subgroups." Social Networks 17:27-56.
———. 1996. "Mapping Interactions Within and Between Cohesive Subgroups." Social Networks 18:93-119.
Freeman, L. C. 1972. "Segregation in Social Networks." Sociological Methods and Research 6:411-30.
Friedkin, N. E. 1984. "Structural Cohesion and Equivalence Explanations of Social Homogeneity." Sociological Methods and Research 12:235-61.
Mizruchi, M. S. 1992. The Structure of Corporate Political Action. Cambridge, MA and London, England: Harvard University Press.
———. 1993. "Cohesion, Equivalence and Similarity of Behavior: a Theoretical and Empirical Assessment." Social Networks 15:275-307.

Class 13. Primary Groups continued.

Summary: (Continuation of last session)

 

Reading: Baker, Wayne. "The Social Structure of a National Securities Market." American Journal of Sociology 89:775-811
Feld, S. L. 1981. "The Focused Organization of Social Ties." American Journal of Sociology 86:1015-35.

 

Assignments: None

 

Background Reading:

Baker, W. E. and R. R. Faulkner. 1993. "The Social Organization of Conspiracy: Illegal Networks in the Heavy Electrical Equipment Industry." American Sociological Review 58:837-60.

Feld. 1991. "Why Your Friends Have More Friends Than You Do." American Journal of Sociology 96:1464-77.

 

Class 14. Roles and Positions

Summary: Cohesive subgroups are only the most obvious structural form that results from interconnected relations. The pattern of ties across relations can be used to induce social roles based on structural equivalence.

 

Reading:

W&F chapter 10. Blockmodeling

White, H. C., S. A. Boorman, and R. L. Breiger. 1976. "Social Structure From Multiple Networks I." American Journal of Sociology 81:730-780.
Padgett, J. F. and C. K. Ansell. 1993. "Robust Action and the Rise of the Medici, 1400-1434." American Journal of Sociology 98:1259-319.

 

Assignments: Blockmodel Assignment

 

Background Reading:

Borgatti, S. P. 1999. "Models of Core / Periphery Structures." Social Networks 21:375-95.
Burt, R. S. 1978. "Cohesion Versus Structural Equivalence As a Basis for Network Sub-Groups." Sociological Methods and Research 7:189-212.
———. "Social Contagion and Innovation: Cohesion Versus Structural Equivalence." American Journal of Sociology 92:1287-335.
———. 1990. "Detecting Role Equivalence." Social Networks 12:83-97.
Brieger, Ronald L. 1976. Career Attributes and Network Structure: A Blockmodel Study of a Biomedical Research Specialty American Sociological Review, Vol. 41: 117-135.
Friedkin, N. E. 1984. "Structural Cohesion and Equivalence Explanations of Social Homogeneity." Sociological Methods and Research 12:235-61.
Lorrain, F. and H. C. White. 1971. "Structural Equivalence of Individuals in Social Networks." Journal of Mathematical Sociology 1:49-80.
Mandel, M. 1983. "Local Roles and Social Networks." American Sociological Review 48:376-86.
Mizruchi, M. S. 1993. "Cohesion, Equivalence and Similarity of Behavior: a Theoretical and Empirical Assessment." Social Networks 15:275-307.

Nadel, A Theory of Social Structure, particularly Chapter 4.

Rossem, R. V. 1996. "The World System Paradigm As General Theory of Development: A Cross-National Test." American Sociological Review 61:508-27.
Smith, D. A. and D. R. White. 1992. "Structure and Dynamics of the Global Economy: Network Analysis of International Trade 1965-1980." Social Forces 70:857-93.

White, D. R. and K. P. Reitz. 1989. "Re-Thinking the Role Concept: Homomorphisms on Social Networks." Pp. 429-88 in Research Methods in Social Network Analysis, Editors L. C. Freeman, D. R. White, and A. K. Romnet. Fairfax, VA: George Mason University Press.

 

Class 15. Peer Influence

Summary: Networks are conduits for the flow of information and influence. Thus, the behavior of individuals is often a complex interaction of individual and interpersonal effects.

Reading:

 Friedkin, N. E. and K. S. Cook. 1990. "Peer Group Influence." Sociological Methods and Research 19(1):122-43.
 Haynie, Dana.  "Delinquent Peers Revisited: Does Network Structure Matter?"
 Cohen, J. M. 1983. "Peer Influence on College Aspirations." Sociology of Education 50:227-241.

 

Assignments: Calculate peer influence measures for example data.

Background Reading:

Kandel, D. B. "On Processes of Peer Influences in Adolescent Drug Use." Alcohol and Substance Abuse in Adolescence, Editor B. Stimmel. New York: Haworth Press.

Friedkin, N.E.  A Structural Theory of Social Influence

 

Class 16.  Network Diffusion

Summary: What network features control diffusion?  What types of networks have the most rapid diffusion?

 

Reading:

Moody, James.  “Network Structure and Diffusion”  Draft manuscript

Valente, Thomas W.  “Network Models and Methods for Studying the Diffusion of Innovations”  in Models and Methods in Social Network Analysis, 2005, Cambridge University Press.

Gerald F. Davis; Henrich R. Greve “Corporate Elite Networks and Governance Changes in the 1980sThe American Journal of Sociology, 103:1-37.

 

Assignments: TBA

Background Reading:

Rogers, Evertt M.  2003 Diffusion of innovations.  Free Press New York

Morris, Martina. Epidemiology and Social Networks: Modeling Structured Diffusion. Sociological Methods and Research. 1993; 22:99-126

Morris, Martina. Sexual Networks and HIV. AIDS 97: Year in Review. 1997; 11(Suppl A):S209-S216.

 

Class 17. Social Exchange

Summary: Networks provide constraints and opportunities for actors. In an exchange setting, this structure will lead to differences in power. We examine both direct exchange between pairs and indirect ‘generalized’ exchange.

 

Reading:
Cook, K. S., R. M. Emerson, M. R. Gillmore, and T. Yamagishi. 1983. "The Distribution of Power in Exchange Networks: Theory and Experimental Evidence." American Journal of Sociology :275-305.
Bearman, P. 1997. "Generalized Exchange." American Journal of Sociology 102(5):1383-415.

 

Assignments: Identify power status of a set of example networks.

 

Background Reading:
Blau, Peter s. Exchange and power in Social Life

Ekeh, P. P. 1974. Social Exchange Theory: The Two Traditions. Cambridge MA: Harvard University Press.
Lawler, E. J. and J. Yoon. 1993. "Power and the Emergence of Commitment Behavior in Negotiated Exchange." American Sociological Review 58:465-81. (optional)

Takahashi, N. 2000. "The Emergence of Generalized Exchange." American Journal of Sociology 105:1105-034

Willer, D. 1999. Network Exchange Theory. Westport, Connecticut: Praeger.

 

Class 18.  Statistical Modeling of Social Networks

Summary: Recent statistical developments have made it possible to model networks statistically, allowing us to incorporate uncertainty from measurement and sampling. In this session we discuss the frame for statistical modeling networks and identify the p* method for doing so.

 

Reading:
Anderson, C., Wasserman, S., and Crouch, B. (1999). A p* primer: Logit models for social networks. Social Networks. 21,37-66

Koehly, Laura M., Steven M. Goodreau, and Martina Morris. “Exponential Family Models for Sampled and Census Network Data”  Sociological Methodology34: 241-271

 

Assignments: Calculate p* on an example graph.

 

Background Reading:
Robins, G., P. Pattison, and S. Wasserman. 1997. "Logit Models and Logistic Regressions for Social Networks: III. Valued Relations." Manuscript .
Pattison, P., and Wasserman, S. 1999. Logit models and logistic regressions for social networks: II. Multivariate relations. British Journal of Mathematical and Statistical Psychology. 52, 169-193
Wasserman, S. and P. Pattison. 1996. "Logit Modles and Logitic Regressions for Social Networks: I. An Introduction to Markov Graphs and P*." Psychometrika 61:401-25.

 

Class 19. Dynamic Properties of social networks

Summary: In this class, we go over two kinds of dynamics in networks: how the network structure changes and how relationship timing affects diffusion through the networks.  We also have some fun with visualizations.

Reading:
Moody, J. 2000. "The Importance of Relationship Timing for STD Diffusion." Social Forces 81:25-56

Moody, J. Daniel McFarland and Skye Bender-deMoll “Dynamic Network Visualizations” Forthcoming, American Journal of Sociology.

Assignments: None

 

Background Reading:

Doreian, P., R. Kapuscinski, D. Krackhardt, and J. Szczypula. 1996. "A Brief History of Balance Through Time." Journal of Mathematical Sociology 21(1-2):113-31.

Hummell, H. J. and W. Sodeur. 1990. "Evaluating Models of Change in Triadic Sociometric Structures." Pp. 281-305 in Social Networks Through Time, Eds Jeroen Weesie and Henk Flap. Utrecht, Netherlands: ISOR.
Morgan, D. L., M. B. Neal, and P. Carder. 1997. "The Stability of Core and Peripheral Networks Over Time." Social Networks 19(1):9-25.
Suitor, J. J., B. Wellman, and D. L. Morgan. 1997. "It's About Time: How, Why and When Networks Change." Social Networks 19(1).
Weesie, J. and H. Flap. 1990. Social Networks Through Time. Utrecht, Netherlannds: ISOR.