  The purpose of this study is threefold: first, to bring reference groups back
into the framework of spiral of silence (SOS) by proposing an extended
framework of dual opinion climate; second, to investigate the boundary
conditions of SOS; third, to identify the characteristics of SOS in terms of
spatial variation and temporal evolution. Modeling SOS with agent-based models,
the findings suggest (1) there is no guarantee of SOS with reference groups
being brought back; (2) Stable existence of SOS is contingent upon the
comparative strength of mass media over reference groups; (3) SOS is
size-dependent upon reference groups and the population; (4) the growth rate of
SOS decreases over time. Thus, this research presents an extension of the SOS
theory.
