Time and network structure: an exploration of change in organizational constellations

The explanation of change in networks structure and contents has been dealt in literature with models that highlight the function of structural elements and more recently with models separating choice and selection of connections at the individual level. The first type of models consider time as one of the agents of change, implicating possibilities for specific forms of connections (e.g. evolution from dyadic to triadic forms, from simple linkage to reciprocity links): according to this view the evolution of a network structure is dependant on the possibilities that are present in the previous stage (the mathematical reference is a Markov chains), such as for the case of preferential attachment phenomena. The second type of models interpret time as the setting of changes: the pace of creation and dissolution of network connections is related to individuals choices and activated by social selection processes that happen in specific time intervals. Both these types of models have been empirically tested, giving satisfactory results; the type of data, however, still influences measurements and computational efficacy. The paper reviews the most typical approaches to longitudinal network approaches and provides empirical examples of analysis of multiple organizational data according to these methodological principles.