[avacado]

"The results are adjusted to make up for this. When all is said and done, the responses of the group oversampled should be in line with their actual share of the population."

How do they adjust it? Blacks make up about 12% of the US population.

[freespirited]

How do they adjust it? Blacks make up about 12% of the US population.

By using a mathematical process called weighting. The tally collected by the survey-takers is the raw data: say 250 votes for Hillary, 200 for Obama, 100 for Edwards. After the weighting is applied, these numbers will change to account for such factors as the oversampling of blacks. For example if 24 black respondents chose Hillary that might be corrected to 19 after weighting.