Actor-based models of network evolution
and their estimation with the SIENA software

Pre-conference workshop, June 12, 2008, attached to
The Harvard Networks in Political Science Conference
June 13-14, 2008

This workshop introduces political scientists to the SIENA program for the statistical analysis of network dynamics for complete networks. Participants get a basic understanding of the program and its underlying actor-based model for network evolution. In lab sessions, the practical steps necessary for obtaining good models of a data set are practiced. It is assumed that participants bring their own laptop (Windows-operated) with the software pre-installed. This page contains three things:
  1. The downloads and installation instructions for the StOCNET software package which allows to run the SIENA program inside a Windows interface.

  2. The workshop program in an overview. Also the workshop transparencies will be posted here, but hat might happen only after the conference.

  3. The assignments for the computer labs - [click here]. Please bring your own printed copy!
Please follow the installation instructions carefully. Given the expected larger number of participants, it will not be possible to address installation issues during the workshop - so do make sure that your copy of the software works before you arrive.

We are looking forward to meeting you in Boston,
the workshop organizers:
  Christian Steglich
University of Groningen http://www.gmw.rug.nl/~steglich 		John T. Scholz
Florida State University
http://polisci.fsu.edu/people/faculty/scholz.htm

[Click here] for the full NIPS conference program.


Software download and installation



Program of the workshop

Note: The following instructions work for Windows-operated computers only. We currently cannot offer support for running StOCNET on other operating systems. While a Linux version of the SIENA software is available at http://stat.gamma.rug.nl/siena.html, instructions how to work with SIENA outside the StOCNET environment fall outside the scope of this workshop.

For installing the StOCNET package, please follow the following instructions step by step:

  1. Uninstall any previous versions of the StOCNET software that may exist on your machine. Manually remove remaining traces of the StOCNET main directory. (This is to make sure that the new installation will not be contaminated by earlier, possibly incompatible settings.)

  2. If you have administrator rights on your computer, please download the StOCNET installer by [clicking here]. We recommend to save the installation file on your computer and run it afterwards. It should guide you through the rest of the installation process.

  3. If you don't have administrator rights on your computer, please download the StOCNET archive [click here]. Unpack the .ZIP-archive you downloaded into a new directory. Open this directory and double-click on "InitializeStocnet.exe" to adjust directory settings.
To unpack the .ZIP archive, make use of WinZip or a compatible data compression software, and make sure that when extracting the files, the directory structure is preserved (in WinZip: the option "Use folder names" is switched on).
  1. You now should have a working version of StOCNET on your computer. In order to check whether you can work with the program, please run the file "StOCNET.exe" (located in the main directory in which you installed StOCNET - note that depending on your Windows Explorer settings, you may not see the ".exe" extension.)

  2. If your startup screen looks like this, everything seems to be alright.
    See you at the workshop for further explorations into the software!

  3. However, if you get a warning message about directory settings and your startup screen looks like this, you need to fix these settings. This should be possible by running "InitializeStocnet.exe" (recommended, see step 3. above), but also can be done manually inside StOCNET - e.g., by clicking "OK" after the warning, and browsing for the proper directory names as in this example. After this, close StOCNET and start anew.
If installation does not succeed, contact Christian Steglich and describe your problem in detail (screenshots and names of the installation directories would be helpful attachments of an e-mail).

2:15

TALK

Introduction to actor-based network evolution models by way of an example
Self-Organizing Policy Networks: Risk, Partner Selection and Cooperation in Estuaries
John T. Scholz, presenting joint work with Ramiro Berardo

2:30

LAB

Introduction to the StOCNET program environment
• data requirements, data format
• working with StOCNET sessions

2:50

TALK

Basic concepts and modelling framework (some mathematics)
• the case of directed networks
• undirected case
• co-evolution with actor variables

3:10

LAB

A first SIENA analysis
• selecting data sets into the roles they play for the analysis
• interpreting output files: descriptives, convergence, significance

3:30

TALK

Model specification
• goodness of fit
• forward & backward model selection strategies

3:50

LAB

A second SIENA analysis
• advanced model specification: rate effects, endowment effects
• score tests

4:10

Q&A

Wrapping up, final round of questions
optional topics:
• statistical power
• estimation methods
• simulating network evolution
• estimating ERGMs in StOCNET with SIENA

4:30

END