What do you think about political opinion?

1. Why must a public opinion sample be a random sample? Why not simply stop a random group of citizens on the street downtown?


2. Why is the sampling error margin so important to the accurate prediction required by modern polling methods?


3. How might a survey be “loaded”? How can the way a question is worded influence how one responds to it? How can question order influence response?

What do you think about political opinion?
1. Why must a public opinion sample be a random sample? Why not simply stop a random group of citizens on the street downtown?





Citizens in the downtown district represent only a segment of the population, i.e. city workers, white collar, homeless, and unemployed mothers with cash.


Samples must come from random clusters to ensure samples represent a diverse group.





2. Why is the sampling error margin so important to the accurate prediction required by modern polling methods?





You could achieve a significantly low error margin, say + or - 1%, but it wouldn't be practicle or affordable. By allowing for + or - 6%, you can conduct a fairly reliable poll without going bankrupt.





3. How might a survey be “loaded”? How can the way a question is worded influence how one responds to it? How can question order influence response?





I'll tell you that one later.