What is the true meaning of the public opinions? - Sachiyo studies.

It had been raining since last night,but cleared up in the afternoon.So I walked in the afternoon. The cherry bolssoms are in full bloom, and looked beautiful everywhere along my walking paths.
Takashi sent me a video on Net from California. It was on what Sachiyo is studying both in Keio university,which is her alma mater, and in Stanford University,(where she studies as a visiting scholar?). By the way,Takashi's wife Sachiyo majored in politics in Keio,so what she is studying in Stanford is,of course, politics.
The title of the video Takashi sent me is "Innovation in Participation : Citizen Engagement in Deliberative Democracy." According to the video,Sachiyo seems to be studying about how to take the public opinion poll,not by the conventioanal way but by an innovative way. They first take the poll at random in the conventional way. Then, they prepare a forum where they invite volunteers who are interested in it from among the respondents to the poll, and let them have a debate. After the forum,they take a poll again. They compare the results of the poll with those of the previous poll.There is a big difference between the results of the two polls.
What is the meaning of the public opinions? What is the approval rating of the government? I have always wondered so far. I hope they will accomplish a good result of their research.