Contends that process analysis of interpersonal networks is a more useful bridge between micro and macro levels of sociological theory than is the analysis of data from large-scale studies, such as social mobility, community organization, and political structure. Suggests that it is through interpersonal networks that small-scale interactions translate into large-scale patterns which, in turn, feed back into small groups. The strength of interpersonal ties, a limited aspect of small-scale interaction, is chosen to show how the use of network analysis can relate this aspect to such varied macro phenomenon as diffusion, social mobility, political organization, and social cohesion. It is argued that the amount of overlap between two individuals' friendship networks varies directly with the strength of their tie to one another. In addition, the effect this principle has on diffusion of influence and information, mobility opportunity, and community organization is examined. Findings show that the personal experience of individuals is closely related to the large-scale aspects of social structure, well beyond the control of particular individuals. Weak ties are shown to be essential to individuals' opportunities and to their integration into communities. On the contrary, strong ties are shown to breed local cohesion and lead to overall fragmentation. (SFL)

Keywords: Weak ties, Network theory, Social networks, Interpersonal relations, Group behavior, Intergroup relations, Social behavior, Social factors, Social psychology, Social structures, Diffusion of innovations, Community development, Trust relationships