How To Know The existence of Public Opinion

Year 1965 during the rebellion Gestapu / PKI. PKI and there is a conflict between supporters of Pancasila which later became New Order. Conflicts occurred after the hearing that there was murder of the General by the PKI.
The rebellion PKI (Gestapu / PKI) took place everywhere, but can be eliminated immediately.
It also hears from newspapers, radio, television and movies, meetings, speeches, lectures and forums, anywhere. The symptoms are called public opinion or public opinion. To understand someone, and public opinion was not easy.

According R.P. Abelson, this is related to:
1. Beliefs about something (belief)
2. What actual or perceived to be his attitude (Attitude)
3. Perception. An experience of objects, events, or relations by concluding the information obtained and interpreted the message and perception is giving meaning to sensory stimuli.