(1979). Social Networks and Psychology. Connections, 2 - INSNA

ANU-MARKOV . AN INTERACTIVE PROGRAM FOR USING MARKOV STATISTICS TO ANALYZE NETWORK DATA .L .D . Thong and A .S . KZovdahZ (Sociology, Arts, Australian National U .)Markov methods provide the means to answer important questions about networks (and other social phenomena). But, although these methods have previously been used to make inferences about networks (e .g . White,1959 ; Beshers and Laumann, 1967 ; Klovdahl, 1976), to date there has been little systematic effort to developthe programs (or packages) that would make Markov methods more readily accessible for network analysis .ANU-MARKOV is an attempt to facilitate the use of Markov statistics for analyzing network data . Thisprogram computes maximum likelihood estimates of transition probabilities from raw data, and then allowsfive relevant statistical tests to be carried out . More specifically, data believed to result from aMarkov process can be tested (a) for the specific values of the transition probabilities, (b) for stationarity,(c) for order and (d) for homogeneity (i .e . to ascertain whether or not data from multiple samples weregenerated by the same process) . In addition, there is a test for the possible relationship between twosets of different states . These tests were developed by Anderson and Goodman (1957) . Finally, the appropriatecorrections for (finite) sample size are also calculated (Sharp, 1975) .The limits of the program depend on the particular test involved . At present, chains of up to 11 statesmay be analyzed, the maximum order that can be tested is 3, and up to 50 transitions may be processed (inthe stationarity test) .The program is written in FORTRAN V .References :Anderson, T .W . and L .A . Goodman . Statistical inference about markov chains . ANNALS OF MATHEMATICAL STATISTICS, 1957, 28, 89-110 .Klovdahl, A .S . Networks in society : The random walk strategy . Working paper . Department of Sociology,Faculty of Arts, The Australian National University, Canberra, 1976 .Sharp, S .A . Corrections to likelihood ratio tests of hypotheses concerning the parameters of Markov chains .BIOMETRIKA, 1975, 62(3), 595-598 .White, H .C . Search parameters for the small world problem . SOCIAL FORCES, 1970, 49, 259-264 .SNAP -SOCIAL NETWORKS ANALYSIS PACKAGEClive Payne, David Deans and Clyde Mitchell (Nuffield College, Oxford)Greg Heil provided a useful review of the final specification for SNAP in Connections Vol II - No . 1but we would like to point out that there appears to be a slight misunderstanding . As yet the package hasnot been implemented . The specification represents the results of only the first stage of the projectand we can only proceed to the second stage of full implementation if we can demonstrate to our sponsorsthat there is sufficient demand for the package . Accordingly readers of Connections are cordially invitedto send for a copy of the final specification . We would be most grateful to receive indications of supportfor the further work on the package . Furthermore, this way of proceeding with package development givespotential users the opportunity to suggest extensions and improvements to be incorporated in the finalversion of the package .