ÇÒÃÊÒà Á©¡.ÇÔªÒ¡Òà 90 »‚·Õè 10 ©ºÑº·Õè 19 ¡Ã¡®Ò¤Á - ¸Ñ¹ÇÒ¤Á 2549 Vikanda Pornsakulvanich* * Department of Marketing, School of Management at Assumption University, Thailand. An Analysis of the Spiral of Silence Theory on Peopleþs Willingness to Express their Political Opinions Noelle-Neumann initiated the idea of the spiral of silence for explaining the power of public opinion on peopleþs ex- pression. The major premise of this theory is that people are reluctant to express their opinions that are opposed to perceived majority public opinion because of fear of isolation (Noelle-Neumann. 1974: 43). She asserted that fear of isolation is a crucial variable, which is −an integral part of all processes of public opinion.× This paper seeks to explain the spiral of silence theory, to summarize studies using spiral of silence theory in explaining peopleþs ex- pression of political opinions, and to provide recommendations for future direction. Abstract People are afraid of being isolated. Hence, fear of isolation influences peopleþs willingness to express their opinions to the public. When people are afraid of being isolated, they will not express their opinions, which they perceive as the minority opinion (Noelle-Neumann, 1974). However, some groups of people are not willing to conform to public opinion. This paper aims to explain the power of public opinion on peopleþs willingness to express their political opinions, to summarize and criticize studies using spiral of silence theory in explaining peopleþs expression of opinions, and to provide conclusion and recommendations for future direction. The spiral of silence theory will be used to explain the power of public opinion. Keywords : spiral of silence, mass media, political opinions, public opinions, social isolation