Discerning the essential structure of social networks is a major task. Blockmodeling is one technique for delineating network structure. Social network data usually contain different types of errors, including missing data that can wreak havoc during data analyses. While we know little about its vulnerability to missing data problems, it is reasonable to expect that it is vulnerable given its positional nature. We focus on actor nonresponse and treatments for this. We examine their impacts on blockmodeling results using simulated and real networks. A set of ‘known’ networks are used, errors due to actor nonresponse are introduced and are then treated in different ways. Blockmodels are fitted to these treated networks and compared to those for the known networks. The outcome indicators are the correspondence of both position memberships and identified blockmodel structures. Both the amount and type of nonresponse, and considered treatments, have an impact on delineated blockmodel structures.
COBISS.SI-ID: 31119197
Recent research on signed networks resulted in the relaxed structural balance (RSB) approach and its subsequent extension to signed two-mode networks involving social actors and social objects. We extend this approach to large signed two-mode networks, and address the methodological issues that arise. We develop tools to partition these types of networks and compare them with other approaches using a recently collected dataset of United Nations General Assembly roll call votes. Although our primary purpose is methodological, we take the first step towards bridging Heider's structural balance theory with recent theorizing in international relations on soft balancing of power processes.
COBISS.SI-ID: 31163741
Proportions of a total, including social network compositions (proportions of partner, family, friends, etc.) lie in a restricted space, which challenges statistical analysis. Such data have to be transformed beforehand, e.g. by logarithms. In the first transformation of this kind Coenders et al. (2011) fitted a factor analysis model to transformed network compositions (by additive log- ratio transformation). The results showed that network compositions are measured with a somewhat higher quality by face-to-face compared to telephone interview. In this study we use isomeric log-ratio transformation and we confirm the earlier findings as well as some other substantive results from other studies on social support networks. The advantage of the new model is its ability to test measurement quality and to test the substaitive effects at the same time. An additional advantage is in a substantively more reasonable and simpler interpretation of the logarithmic transformation indices.
COBISS.SI-ID: 31612253
In the article two seemingly distinct perspectives regarding the modeling of network dynamics are combined. One perspective is found in the work of physicists and mathematicians who formally introduced the small world model and the mechanism of preferential attachment. The other perspective is sociological and focuses on the process of cumulative advantage and considers the agency of individual actors in a network. We test hypotheses, based on work drawn from these perspectives, regarding the structure and dynamics of scientific collaboration networks. The data we use are for four scientific disciplines in the Slovene system of science. The results deal with the overall topology of these networks and specific processes that generate them. The two perspectives can be joined to mutual benefit. Within this combined approach, the presence of smallworld Structures was confirmed. However preferential attachment is far more complex than advocates of a single autonomous mechanism claim.
COBISS.SI-ID: 30657885
The paper introduces the use of blockmodeling in the microlevel study of the internal structure of coauthorship networks over time. Variations in scientific productivity and researcher or research group visibility were determined by observing authors’ role in the coreperiphery structure and crossing this information with bibliometric data. The used approach combines bibliometric and social network analysis to explore scientific collaboration networks and monitor individual and group careers from new perspectives. Its application on a smallscale case study is intended as an example and can be used in other disciplines.
COBISS.SI-ID: 31397725