TY - JOUR
T1 - Assessing and accounting for time heterogeneity in stochastic actor oriented models
AU - Lospinoso, Joshua A.
AU - Schweinberger, Michael
AU - Snijders, Tom A.B.
AU - Ripley, Ruth M.
N1 - Funding Information:
Campbell et al. (2008) conducted a study funded by the UK Medical Research Council which involved peer-nominated students aged 12–14. These individuals underwent intensive training on how to discourage their peers from smoking. The complete dataset contains data on over 10,000 students.8 Smoking behavior, friendship nomination, sex, age, parental smoking habits, family affluence, and nominal information on classroom membership are all features of the dataset. There are a number of interesting research questions supported by this study. In the following analysis, we wish to find whether an ego’s smoking behavior affects nomination of alters on the basis of the alter’s smoking behavior (i.e. selection).9
Funding Information:
This research was funded in part by U.S. Army Project Number 611102B74F and MIPR Number 9FDATXR048 (JAL); by U.S. N.I.H. (National Institutes of Health) Grant Number 1R01HD052887-01A2, for the project Adolescent Peer Social Network Dynamics and Problem Behavior (TABS and RMR); and by U.S. N.I.H. (National Institutes of Health) Grant Number 1R01GM083603-01 (MS). The authors are grateful to Professor Laurence Moore of the Cardiff Institute for Society, Health and Ethics (CISHE) for the permission to use the ASSIST data and to Christian Steglich for his help with using these data.
PY - 2011/7
Y1 - 2011/7
N2 - This paper explores time heterogeneity in stochastic actor oriented models (SAOM) proposed by Snijders (Sociological methodology. Blackwell, Boston, pp 361-395, 2001) which are meant to study the evolution of networks. SAOMs model social networks as directed graphs with nodes representing people, organizations, etc., and dichotomous relations representing underlying relationships of friendship, advice, etc. We illustrate several reasons why heterogeneity should be statistically tested and provide a fast, convenient method for assessment and model correction. SAOMs provide a flexible framework for network dynamics which allow a researcher to test selection, influence, behavioral, and structural properties in network data over time. We show how the forward-selecting, score type test proposed by Schweinberger (Chapter 4: Statistical modeling of network panel data: goodness of fit. PhD thesis, University of Groningen 2007) can be employed to quickly assess heterogeneity at almost no additional computational cost. One step estimates are used to assess the magnitude of the heterogeneity. Simulation studies are conducted to support the validity of this approach. The ASSIST dataset (Campbell et al. In Lancet 371(9624):1595-1602, 2008) is reanalyzed with the score type test, one step estimators, and a full estimation for illustration. These tools are implemented in the RSiena package, and a brief walkthrough is provided.
AB - This paper explores time heterogeneity in stochastic actor oriented models (SAOM) proposed by Snijders (Sociological methodology. Blackwell, Boston, pp 361-395, 2001) which are meant to study the evolution of networks. SAOMs model social networks as directed graphs with nodes representing people, organizations, etc., and dichotomous relations representing underlying relationships of friendship, advice, etc. We illustrate several reasons why heterogeneity should be statistically tested and provide a fast, convenient method for assessment and model correction. SAOMs provide a flexible framework for network dynamics which allow a researcher to test selection, influence, behavioral, and structural properties in network data over time. We show how the forward-selecting, score type test proposed by Schweinberger (Chapter 4: Statistical modeling of network panel data: goodness of fit. PhD thesis, University of Groningen 2007) can be employed to quickly assess heterogeneity at almost no additional computational cost. One step estimates are used to assess the magnitude of the heterogeneity. Simulation studies are conducted to support the validity of this approach. The ASSIST dataset (Campbell et al. In Lancet 371(9624):1595-1602, 2008) is reanalyzed with the score type test, one step estimators, and a full estimation for illustration. These tools are implemented in the RSiena package, and a brief walkthrough is provided.
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U2 - 10.1007/s11634-010-0076-1
DO - 10.1007/s11634-010-0076-1
M3 - Article
AN - SCOPUS:79957800983
SN - 1862-5347
VL - 5
SP - 147
EP - 176
JO - Advances in Data Analysis and Classification
JF - Advances in Data Analysis and Classification
IS - 2
ER -